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Sample records for liquid-scintillator detector lena

  1. The next-generation liquid-scintillator neutrino observatory LENA

    CERN Document Server

    Wurm, Michael; Bezrukov, Leonid B; Bick, Daniel; Blümer, Johannes; Choubey, Sandhya; Ciemniak, Christian; D'Angelo, Davide; Dasgupta, Basudeb; Dighe, Amol; Domogatsky, Grigorij; Dye, Steve; Eliseev, Sergey; Enqvist, Timo; Erykalov, Alexey; von Feilitzsch, Franz; Fiorentini, Gianni; Fischer, Tobias; Göger-Neff, Marianne; Grabmayr, Peter; Hagner, Caren; Hellgartner, Dominikus; Hissa, Johannes; Horiuchi, Shunsaku; Janka, Hans-Thomas; Jaupart, Claude; Jochum, Josef; Kalliokoski, Tuomo; Kuusiniemi, Pasi; Lachenmaier, Tobias; Lazanu, Ionel; Learned, John G; Lewke, Timo; Lombardi, Paolo; Lorenz, Sebastian; Lubsandorzhiev, Bayarto; Ludhova, Livia; Loo, Kai; Maalampi, Jukka; Mantovani, Fabio; Marafini, Michela; Maricic, Jelena; Undagoitia, Teresa Marrodán; McDonough, William F; Miramonti, Lino; Mirizzi, Alessandro; Meindl, Quirin; Mena, Olga; Möllenberg, Randolph; Nahnhauer, Rolf; Nesterenko, Dmitry; Novikov, Yuri N; Nuijten, Guido; Oberauer, Lothar; Pakvasa, Sandip; Palomares-Ruiz, Sergio; Pallavicini, Marco; Pascoli, Silvia; Patzak, Thomas; Peltoniemi, Juha; Potzel, Walter; Räihä, Tomi; Raffelt, Georg G; Ranucci, Gioacchino; Razzaque, Soebur; Rummukainen, Kari; Sarkamo, Juho; Sinev, Valerij; Spiering, Christian; Stahl, Achim; Thorne, Felicitas; Tippmann, Marc; Tonazzo, Alessandra; Trzaska, Wladyslaw H; Vergados, John D; Wiebusch, Christopher; Winter, Jürgen

    2011-01-01

    We propose the liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) as a next-generation neutrino observatory on the scale of 50 kt. The outstanding successes of the Borexino and KamLAND experiments demonstrate the large potential of liquid-scintillator detectors in low-energy neutrino physics. LENA's physics objectives comprise the observation of astrophysical and terrestrial neutrino sources as well as the investigation of neutrino oscillations. In the GeV energy range, the search for proton decay and long-baseline neutrino oscillation experiments complement the low-energy program. Based on the considerable expertise present in European and international research groups, the technical design is sufficiently mature to allow for an early start of detector realization.

  2. Topological track reconstruction in liquid scintillator and LENA as a far-detector in an LBNO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Sebastian

    2016-12-15

    Unsegmented liquid scintillator (LSc) neutrino detectors have proven to be successful instruments of neutrino physics. They usually measure terrestrial and astrophysical low-energy (LE) neutrinos and antineutrinos with energies up to some tens of MeV. Designs for next-generation detectors based on this technology intend to use several tens of kilotons of LSc. Two examples are the Low Energy Neutrino Astronomy (LENA) project with 50 kt considered in Europe and the Jiangmen Underground Neutrino Observatory (JUNO) with 20 kt already under construction in China. A key factor to reach the scientific goals of these projects, e.g., the determination of the neutrino mass ordering (MO) in the case of JUNO, will be the efficient rejection of background from radioisotopes produced by cosmogenic muons. This requires accurate reconstructions of extended muon event topologies in the LSc volume.The first part of this work is about the implementation of a novel, iterative track reconstruction procedure for unsegmented LSc detectors and a basic evaluation of its performance with the LENA detector simulation. The ultimate goal of the new method is to reconstruct the spatial number density distribution of optical photon emissions. This will give access to a charged particle's differential energy loss dE/dx in LSc and resolve details of an event's topology, e.g., induced particle showers. Visual comparisons of reconstruction outcomes with Monte Carlo (MC) truths already provide evidence for this capability. First quantitative results were extracted from the 3D reconstruction data of fully-contained muons in the kinetic energy range from 1 to 10 GeV: Despite some well understood systematic effects in the current method to find start and end point of a track, resolutions

  3. Characterization of liquid scintillation detectors

    CERN Document Server

    Schmidt, D; Böttger, R; Klein, H; Lebreton, L; Neumann, S; Nolte, R; Pichenot, G

    2002-01-01

    Five scintillation detectors of different scintillator size and type were characterized. The pulse height scale was calibrated in terms of electron light output units using photon sources. The response functions for time-of-flight (TOF)-selected monoenergetic neutrons were experimentally determined and also simulated with the NRESP code over a wide energy range. A comparison of the measured and calculated response functions allows individual characteristics of the detectors to be determined and the response matrix to be reliably derived. Various applications are discussed.

  4. Study Performance of Liquid Scintillation Fiber Detector

    CERN Document Server

    Zhang, Yongpeng; Lu, Haoqi; Zhang, Peng; Zhang, Chengcai; Yang, Changgen

    2016-01-01

    Liquid scintillator (LS) with optical fiber detector (LSOF detector) is a new type of detector, which has been applied in large-scale particle physics experiments in recent years. We were proposing LSOF detector as one option of top veto detector in Jiangmen Underground Neutrino Observatory (JUNO) experiment. The prototype detector was located in laboratory of the institute of high energy physics (IHEP). From prototype study, we found that the detector have a good performance and can satisfy JUNO requirement. The detection efficiency of cosmic ray muon is greater than 98% and can collect 58 photon electrons (p.e.) when muon is going through the detector. Further more, the relationship between p.e., material reflectivity and LS depth are studied. We also compared the data with Monte Carlo simulation, and they have a good agreement with each other.

  5. Large-scale liquid scintillation detectors for solar neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Benziger, Jay B.; Calaprice, Frank P. [Princeton University Princeton, Princeton, NJ (United States)

    2016-04-15

    Large-scale liquid scintillation detectors are capable of providing spectral yields of the low energy solar neutrinos. These detectors require > 100 tons of liquid scintillator with high optical and radiopurity. In this paper requirements for low-energy neutrino detection by liquid scintillation are specified and the procedures to achieve low backgrounds in large-scale liquid scintillation detectors for solar neutrinos are reviewed. The designs, operations and achievements of Borexino, KamLAND and SNO+ in measuring the low-energy solar neutrino fluxes are reviewed. (orig.)

  6. Probing the Earth's interior with the LENA detector

    CERN Document Server

    Hochmuth, K A; Fields, B D; Undagoitia, T M; Oberauer, L; Potzel, W; Wurm, M; Hochmuth, Kathrin A.; Feilitzsch, Franz v.; Fields, Brian D.; Undagoitia, Teresa Marrodan; Oberauer, Lothar; Potzel, Walter; Wurm, Michael

    2006-01-01

    A future large-volume liquid scintillator detector such as the proposed 50 kton LENA (Low Energy Neutrino Astronomy) detector would provide a high-statistics measurement of terrestrial antineutrinos originating from $\\beta$-decays of the uranium and thorium chains. Additionally, the neutron is scattered in the forward direction in the detection reaction $\\bar\

  7. Reactor Neutrino Experiments with a Large Liquid Scintillator Detector

    CERN Document Server

    Kopp, J F; Merle, A; Rolinec, M

    2007-01-01

    We discuss several new ideas for reactor neutrino oscillation experiments with a Large Liquid Scintillator Detector. We consider two different scenarios for a measurement of the small mixing angle $\\theta_{13}$ with a mobile $\\bar{\

  8. Explore nuclearites in a large liquid scintillator neutrino detector

    CERN Document Server

    Guo, Wan-Lei; Lin, Tao; Wang, Zhi-Min

    2016-01-01

    We take the JUNO experiment as an example to explore nuclearites in the future large liquid scintillator detector. Comparing to the previous calculations, the visible energy of nuclearites across the liquid scintillator will be reestimated for the liquid scintillator based detector. Then the JUNO sensitivities to the nuclearite flux are presented. It is found that the JUNO projected sensitivities can be better than $7.7 \\times 10^{-17} {\\rm cm^{-2} s^{-1} sr^{-1}}$ for the nuclearite mass $10^{15} \\; {\\rm GeV} \\leq M \\leq 10^{24}$ GeV and initial velocity $10^{-4} \\leq \\beta_0 \\leq 10^{-1}$ with a 20 year running. Note that the JUNO will give the most stringent limits for downgoing nuclearites with $1.6 \\times 10^{13} \\; {\\rm GeV} \\leq M \\leq 4.0 \\times 10^{15}$ GeV and a typical galactic velocity $\\beta_0 = 10^{-3}$.

  9. How to observe 8B solar neutrinos in liquid scintillator detectors

    CERN Document Server

    Ianni, A; Villante, F L

    2016-01-01

    We show that liquid organic scintillator detectors (e.g., KamLAND and Borexino) can measure the 8B solar neutrino flux by means of the nu_e charged current interaction with the 13C nuclei naturally contained in the scintillators. The neutrino events can be identified by exploiting the time and space coincidence with the subsequent decay of the produced 13N nuclei. We perform a detailed analysis of the background in KamLAND, Borexino and in a possible liquid scintillator detector at SNOLab, showing that the 8B solar neutrino signal can be extracted with a reasonable uncertainty in a few years of data taking. KamLAND should be able to extract about 18 solar neutrino events from the already collected data. Prospects for gigantic scintillator detectors (such as LENA) are also studied.

  10. The Research Progress of the Liquid Scintillation Detectors on Neutron Measurement

    Institute of Scientific and Technical Information of China (English)

    CHENG; Yi-mei; XU; Xiao-ming; ZHU; Li-qun; BAI; Lei; XU; Zhen; HE; Li-xia; YIN; Hong-he

    2012-01-01

    <正>The research for liquid scintillation detectors on neutron measurement is one of the study objects of technique research on neutron measurement. According to the task requirements, we accomplished the purchase of some detectors and related performance testing. The purchased liquid scintillation detectors BC-501A is produced by Saint-Gobain Company. According to the formulated performance testing outlines for liquid scintillation detectors, we conducted

  11. Antineutrino Geophysics with Liquid Scintillator Detectors

    CERN Document Server

    Rothschild, C G; Calaprice, F P; Rothschild, Casey G.; Chen, Mark C.; Calaprice, Frank P.

    1997-01-01

    Detecting the antineutrinos emitted by the decay of radioactive elements in the mantle and crust could provide a direct measurement of the total abundance of uranium and thorium in the Earth. In calculating the antineutrino flux at specific sites, the local geology of the crust and the background from the world's nuclear power reactors are important considerations. Employing a global crustal map, with type and thickness data, and using recent estimates of the uranium and thorium distribution in the Earth, we calculate the antineutrino event rate for two new neutrino detectors. We show that spectral features allow terrestrial antineutrino events to be identified above reactor antineutrino backgrounds and that the uranium and thorium contributions can be separately determined.

  12. Organic liquid scintillation detector shape and volume impact on radiation portal monitors

    Science.gov (United States)

    Paff, Marc G.; Clarke, Shaun D.; Pozzi, Sara A.

    2016-07-01

    We have developed and tested a radiation portal monitor using organic liquid scintillation detectors. In order to optimize our system designs, neutron measurements were carried out with three organic liquid scintillation detectors of different shapes and sizes, along with a 3He radiation portal monitor (RPM) as a reference. The three liquids tested were a 7.62 cm diameter by 7.62 cm length cylindrical active volume organic liquid scintillation detector, a 12.7 cm diameter by 12.7 cm length cylindrical active volume organic liquid scintillation detector, and a 25 cm by 25 cm by 10 cm "paddle" shaped organic liquid scintillation detector. Background and Cf-252 neutron measurements were recorded to allow for a comparison of neutron intrinsic efficiencies as well as receiver operating characteristics (ROC) curves between detectors. The 12.7 cm diameter cylindrical active volume organic liquid scintillation detector exhibited the highest intrinsic neutron efficiency (54%) of all three liquid scintillators. An ROC curve analysis for a heavily moderated Cf-252 measurement showed that using the 12.7 cm diameter by 12.7 cm length cylindrical active volume Eljen EJ309 organic liquid scintillation detector would result in the fewest needed detector units in order to achieve a near 100% positive neutron alarm rate while maintaining a better than 1 in 10,000 false alarm rate on natural neutron background. A small number of organic liquid scintillation detectors could therefore be a valid alternative to 3He in some RPM applications.

  13. ecCNO solar neutrinos: A challenge for gigantic ultra-pure liquid scintillator detectors

    Science.gov (United States)

    Villante, F. L.

    2015-03-01

    Neutrinos produced in the Sun by electron capture reactions on 13N, 15O and 17F, to which we refer as ecCNO neutrinos, are not usually considered in solar neutrino analysis since the expected fluxes are extremely low. The experimental determination of this sub-dominant component of the solar neutrino flux is very difficult but could be rewarding since it provides a determination of the metallic content of the solar core and, moreover, probes the solar neutrino survival probability in the transition region at Eν ∼ 2.5 MeV. In this Letter, we suggest that this difficult measure could be at reach for future gigantic ultra-pure liquid scintillator detectors, such as LENA.

  14. ecCNO solar neutrinos: A challenge for gigantic ultra-pure liquid scintillator detectors

    Directory of Open Access Journals (Sweden)

    F.L. Villante

    2015-03-01

    Full Text Available Neutrinos produced in the Sun by electron capture reactions on 13N, 15O and 17F, to which we refer as ecCNO neutrinos, are not usually considered in solar neutrino analysis since the expected fluxes are extremely low. The experimental determination of this sub-dominant component of the solar neutrino flux is very difficult but could be rewarding since it provides a determination of the metallic content of the solar core and, moreover, probes the solar neutrino survival probability in the transition region at Eν∼2.5 MeV. In this Letter, we suggest that this difficult measure could be at reach for future gigantic ultra-pure liquid scintillator detectors, such as LENA.

  15. A liquid scintillator detector with wavelength-shifting fibre readout

    CERN Document Server

    Doucet, M; Grégoire, G; Panman, J; Zucchelli, P

    2000-01-01

    A technique based on liquid scintillator with wavelength-shiftingfibre readout is interesting for large-mass neutrino detectors.In this paper we present the first results obtained with a laboratoryprototype assembled at CERN. In the configuration tested, a large light yield has been observed and attenuation lengths of the order of 3.2~m have been measured. As a comparison, we also measured the attenuation length of the fibres in air using the same setup. No significant difference in attenuation length between the fibres in air and in liquid was measured.

  16. Light yield measurements in a liquid scintillator detector with wavelength-shifting fibre readout

    CERN Document Server

    Doucet, M; Grégoire, G; Panman, J; Zucchelli, P

    2001-01-01

    A technique based on liquid scintillator with wavelength-shiftingfibre readout is interesting for large-mass neutrino detectors. In this paper, we present results obtained with a laboratoryprototype assembled at CERN. Mixtures made of economical chemicalcomponents were compared to commercial liquid scintillators. Thelight yield was also studied as a function of fibre diameter, fibreposition, and surface quality of the container.

  17. Organic liquid scintillation detector shape and volume impact on radiation portal monitors

    Energy Technology Data Exchange (ETDEWEB)

    Paff, Marc G.; Clarke, Shaun D.; Pozzi, Sara A.

    2016-07-21

    We have developed and tested a radiation portal monitor using organic liquid scintillation detectors. In order to optimize our system designs, neutron measurements were carried out with three organic liquid scintillation detectors of different shapes and sizes, along with a {sup 3}He radiation portal monitor (RPM) as a reference. The three liquids tested were a 7.62 cm diameter by 7.62 cm length cylindrical active volume organic liquid scintillation detector, a 12.7 cm diameter by 12.7 cm length cylindrical active volume organic liquid scintillation detector, and a 25 cm by 25 cm by 10 cm “paddle” shaped organic liquid scintillation detector. Background and Cf-252 neutron measurements were recorded to allow for a comparison of neutron intrinsic efficiencies as well as receiver operating characteristics (ROC) curves between detectors. The 12.7 cm diameter cylindrical active volume organic liquid scintillation detector exhibited the highest intrinsic neutron efficiency (54%) of all three liquid scintillators. An ROC curve analysis for a heavily moderated Cf-252 measurement showed that using the 12.7 cm diameter by 12.7 cm length cylindrical active volume Eljen EJ309 organic liquid scintillation detector would result in the fewest needed detector units in order to achieve a near 100% positive neutron alarm rate while maintaining a better than 1 in 10,000 false alarm rate on natural neutron background. A small number of organic liquid scintillation detectors could therefore be a valid alternative to {sup 3}He in some RPM applications.

  18. Measuring the attenuation length in liquid scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Hellgartner, Dominikus; Oberauer, Lothar; Prummer, Sabrina; Sawatzki, Julia; Zimmer, Vincenz [Technische Universitaet Muenchen, Physik Departement E15, James Franck Strasse, 85748 Garching (Germany); Ulrich, Andreas [Technische Universitaet Muenchen, Physik Departement E12, James Franck Strasse, 85748 Garching (Germany)

    2015-07-01

    The next generation of liquid scintillator detectors like the proposed LENA detector or the planned JUNO detector will feature diameters of order 30 m. Due to this vast size, the optical quality of the scintillator is of crucial importance. To determine the attenuation length of liquid scintillators, an experiment with a 5 m long measurement section was set-up in the underground laboratory in Garching. The current set-up of the experiment is presented along with a discussion of the results of the first measurements. Additionally, there is an outlook towards possible upgrades of the experiment in the future.

  19. Discovery potential for supernova relic neutrinos with slow liquid scintillator detectors

    Science.gov (United States)

    Wei, Hanyu; Wang, Zhe; Chen, Shaomin

    2017-06-01

    Detection of supernova relic neutrinos could provide key support for our current understanding of stellar and cosmological evolution, and precise measurements of these neutrinos could yield novel insights into the universe. In this paper, we studied the detection potential of supernova relic neutrinos using linear alkyl benzene (LAB) as a slow liquid scintillator. The linear alkyl benzene features good separation of Cherenkov and scintillation lights, thereby providing a new route for particle identification. We further addressed key issues in current experiments, including (1) the charged current background of atmospheric neutrinos in water Cherenkov detectors and (2) the neutral current background of atmospheric neutrinos in typical liquid scintillator detectors. A kiloton-scale LAB detector at Jinping with O(10) years of data could discover supernova relic neutrinos with a sensitivity comparable to that of large-volume water Cherenkov detectors, typical liquid scintillator detectors, and liquid argon detectors.

  20. Data analysis in solar neutrinos liquid-scintillator detectors

    Energy Technology Data Exchange (ETDEWEB)

    Testera, G. [INFN, Genova (Italy)

    2016-04-15

    This paper focuses on the description of some of the methods developed to extract the solar neutrino signal from the background by the two running experiments (Borexino and Kamland) based on the use of a large volume of liquid scintillator. (orig.)

  1. Liquid scintillator composition optimization for use in ultra-high energy cosmic ray detector systems

    Science.gov (United States)

    Beznosko, Dmitriy; Batyrkhanov, Ayan; Iakovlev, Alexander; Yelshibekov, Khalykbek

    2017-06-01

    The Horizon-T (HT) detector system and the currently under R&D HT-KZ detector system are designed for the detection of Extensive Air Showers (EAS) with energies above ˜1016 eV (˜1017 eV for HT-KZ). The main challenges in both detector systems are the fast time resolutions needed for studying the temporary structure of EAS, and the extremely wide dynamic range needed to study the spatial distribution of charged particles in EAS disks. In order to detect the low-density of charged particles far from the EAS axis, a large-area detector is needed. Liquid scintillator with low cost would be a possible solution for such a detector, including the recently developed safe and low-cost water-based liquid scintillators. Liquid organic scintillators give a fast and high light yield (LY) for charged particle detection. It is similar to plastic scintillator in properties but is cost effective for large volumes. With liquid scintillator, one can create detection volumes that are symmetric and yet retain high LY detection. Different wavelength shifters affect the scintillation light by changing the output spectrum into the best detection region. Results of the latest studies of the components optimization in the liquid scintillator formulae are presented.

  2. Discovery potential for supernova relic neutrinos with slow liquid scintillator detectors

    CERN Document Server

    Wei, Hanyu; Chen, Shaomin

    2016-01-01

    The detection of supernova relic neutrinos would provide a key support for our current understanding of stellar and cosmological evolution, and precise measurements of them would further give us an insight of the profound universe. In this paper we study the potential to detect supernova relic neutrinos using linear alkyl benzene, LAB, as a slow liquid scintillator, which features a good separation of Cherenkov and scintillation lights, thus providing a new ability in particle identification. We also address key issues of current experiments, including 1) the charged current background of atmospheric neutrinos in water Cherenkov detectors, and 2) the neutral current background of atmospheric neutrinos in typical liquid scintillator detectors. With LAB, a kiloton-scale detector, like the SNO, KamLAND, and the future Jinping neutrino detectors, with $\\mathcal{O}$(10) years of data, would have the sensitivity to discover supernova relic neutrinos, which is comparable to large-volume water Cherenkov, typical liqu...

  3. SNM detection by means of thermal neutron interrogation and a liquid scintillation detector

    Science.gov (United States)

    Ocherashvili, A.; Roesgen, E.; Beck, A.; Caspi, E. N.; Mosconi, M.; Crochemore, J.-M.; Pedersen, B.

    2012-03-01

    The feasibility of using a pulsed neutron generator in a graphite assembly together with a single liquid scintillation detector for the detection of special nuclear materials is investigated. Thermal source neutrons induce fission in fissile material present in the sample. By means of pulse shape discrimination the detector signals from fast fission neutrons are easily identified among the signals from gamma rays and the interrogating thermal neutrons. The method has potential in applications for detection of special nuclear materials in shielded containers.

  4. The research program of the Liquid Scintillation Detector (LSD) in the Mont Blanc Laboratory

    Science.gov (United States)

    Dadykin, V. L.; Yakushev, V. F.; Korchagin, P. V.; Korchagin, V. B.; Malgin, A. S.; Ryassny, F. G.; Ryazhskaya, O. G.; Talochkin, V. P.; Zatsepin, G. T.; Badino, G.

    1985-01-01

    A massive (90 tons) liquid scintillation detector (LSD) has been running since October 1984 in the Mont Blanc Laboratory at a depth of 5,200 hg/sq cm of standard rock. The research program of the experiment covers a variety of topics in particle physics and astrophysics. The performance of the detector, the main fields of research are presented and the preliminary results are discussed.

  5. Occulting Light Concentrators in Liquid Scintillator Neutrino Detectors

    Science.gov (United States)

    Buizza Avanzini, Margherita; Cabrera, Anatael; Dusini, Stefano; Grassi, Marco; He, Miao; Wu, Wenjie

    2017-09-01

    The experimental efforts characterizing the era of precision neutrino physics revolve around collecting high-statistics neutrino samples and attaining an excellent energy and position resolution. Next generation liquid-based neutrino detectors, such as JUNO, HyperKamiokande, etc, share the use of a large target mass, and the need of pushing light collection to the edge for maximal calorimetric information. Achieving high light collection implies considerable costs, especially when considering detector masses of several kt. A traditional strategy to maximize the effective photo-coverage with the minimum number of PMTs relies on Light Concentrators (LC), such as Winston Cones. In this paper, the authors introduce a novel concept called Occulting Light Concentrators (OLC), whereby a traditional LC gets tailored to a conventional PMT, by taking into account its single-photoelectron collection efficiency profile and thus occulting the worst performing portion of the photocathode. Thus, the OLC shape optimization takes into account not only the optical interface of the PMT, but also the maximization of the PMT detection performances. The light collection uniformity across the detector is another advantage of the OLC system. By considering the case of JUNO, we will show OLC capabilities in terms of light collection and energy resolution.

  6. Discriminating cosmic muons and radioactivity using a liquid scintillation fiber detector

    Science.gov (United States)

    Zhang, Y. P.; Xu, J. L.; Lu, H. Q.; Zhang, P.; Zhang, C. C.; Yang, C. G.

    2017-03-01

    In the case of underground experiments for neutrino physics or rare event searches, the background caused by cosmic muons contributes significantly and therefore must be identified and rejected. We proposed and optimized a new detector using liquid scintillator with wavelenghth-shifting fibers which can be employed as a veto detector for cosmic muons background rejection. From the prototype study, it has been found that the detector has good performances and is capable of discriminating between muons induced signals and environmental radiation background. Its muons detection efficiency is greater than 98%, and on average, 58 photo-electrons (p.e.) are collected when a muon passes through the detector. To optimize the design and enhance the collection of light, the reflectivity of the coating materials has been studied in detail. A Monte Carlo simulation of the detector has been developed and compared to the performed measurements showing a good agreement between data and simulation results.

  7. Characterization of liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system

    Energy Technology Data Exchange (ETDEWEB)

    Lombigit, L., E-mail: lojius@nm.gov.my; Yussup, N., E-mail: nolida@nm.gov.my; Ibrahim, Maslina Mohd; Rahman, Nur Aira Abd; Rawi, M. Z. M. [Instrumentation Group, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

    2015-04-29

    A digital n/γ pulse shape discrimination (PSD) system is currently under development at Instrumentation and Automation Centre, Malaysian Nuclear Agency. This system aims at simultaneous detection of fast neutron and gamma ray in mixed radiations environment. This work reports the system characterization performed on the liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system. The characterization involves measurement of electron light output from the BC-501A detector and energy channels calibration of the pulse height spectra acquired with DPSD system using set of photon reference sources. The main goal of this experiment is to calibrate the ADC channel of our DPSD system, characterized the BC-501 detector and find the position of Compton edge which later could be used as threshold for the n/γ PSD experiment. The detector resolution however is worse as compared to other published data but it is expected as our detector has a smaller active volume.

  8. Development and Characterization of 6Li-doped Liquid Scintillator Detectors for PROSPECT

    Science.gov (United States)

    Gaison, Jeremy; Prospect Collaboration

    2016-09-01

    PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, is a phased reactor antineutrino experiment designed to search for eV-scale sterile neutrinos via short-baseline neutrino oscillations and to make a precision measurement of the 235U reactor antineutrino spectrum. A multi-ton, optically segmented detector will be deployed at Oak Ridge National Laboratory's (ORNL) High Flux Isotope Reactor (HFIR) to measure the reactor spectrum at baselines ranging from 7-12m. A two-segment detector prototype with 50 liters of active liquid scintillator target has been built to verify the detector design and to benchmark its performance. In this presentation, we will summarize the performance of this detector prototype and describe the optical and energy calibration of the segmented PROSPECT detectors.

  9. A rope-net support system for the liquid scintillator detector for the SNO+ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bialek, A., E-mail: abialek@snolab.ca [University of Alberta, Edmonton (Canada); Chen, M. [Queen' s University, Kingston (Canada); Cleveland, B. [SNOLAB, Lively (Canada); Gorel, P.; Hallin, A. [University of Alberta, Edmonton (Canada); Harvey, P.J.; Heise, J. [Queen' s University, Kingston (Canada); Kraus, C. [Laurentian University, Sudbury (Canada); Krauss, C.B. [University of Alberta, Edmonton (Canada); Lawson, I. [SNOLAB, Lively (Canada); Ng, C.J.; Pinkney, B. [University of Alberta, Edmonton (Canada); Rogowsky, D.M. [Rogowsky Engineering Ltd, AECOM Canada Ltd (Canada); Sibley, L.; Soluk, R.; Soukup, J. [University of Alberta, Edmonton (Canada); Vázquez-Jáuregui, E. [SNOLAB, Lively (Canada); Laurentian University, Sudbury (Canada)

    2016-08-11

    The detector for the SNO+ experiment consists of 780 000 kg of liquid scintillator contained in an acrylic vessel that is surrounded by water. A mechanical system has been installed to counteract the 1.25 MN of buoyant force on the acrylic and prevent the vessel from moving. The system is a rope net, designed using a Finite Element Analysis to calculate the amount of stress on the acrylic induced by the ropes, hydrostatic pressures and gravity. A dedicated test was performed to measure strains in the acrylic arising from the complex geometry of the knots in the rope system. The ratio between measured and FEA calculated strains was 1.3.

  10. Fluorescence decay-time constants in organic liquid scintillators.

    Science.gov (United States)

    Marrodán Undagoitia, T; von Feilitzsch, F; Oberauer, L; Potzel, W; Ulrich, A; Winter, J; Wurm, M

    2009-04-01

    The fluorescence decay-time constants have been measured for several scintillator mixtures based on phenyl-o-xylylethane (PXE) and linear alkylbenzene (LAB) solvents. The resulting values are of relevance for the physics performance of the proposed large-volume liquid scintillator detector Low Energy Neutrino Astronomy (LENA). In particular, the impact of the measured values to the search for proton decay via p-->K(+)nu is evaluated in this work.

  11. Unfolding the fast neutron spectra of a BC501A liquid scintillation detector using GRAVEL method

    CERN Document Server

    Chen, Yonghao; Lei, Jiarong; An, Li; Zhang, Xiaodong; Shao, Jianxiong; Zheng, Pu; Wang, Xinhua

    2013-01-01

    Accurate knowledge of the neutron energy spectra is useful in basic research and applications. The overall procedure of measuring and unfolding the fast neutron energy spectra with BC501A liquid scintillation detector is described. The recoil proton spectrum of Am-Be neutrons was obtained experimentally. With the NRESP7 code, the response matrix of detector was simulated. Combining the recoil proton spectrum and response matrix, the unfolding of neutron spectra was performed by GRAVEL iterative algorithm. A MatLab program based on the GRAVEL method was developed. The continuous neutron spectrum of Am-Be source and monoenergetic neutron spectrum of D-T source have been unfolded successfully and are in good agreement with their standard reference spectra. The unfolded Am-Be spectrum are more accurate than the spectra unfolded by artificial neural networks in recent years.

  12. Unfolding the fast neutron spectra of a BC501A liquid scintillation detector using GRAVEL method

    Science.gov (United States)

    Chen, YongHao; Chen, XiMeng; Lei, JiaRong; An, Li; Zhang, XiaoDong; Shao, JianXiong; Zheng, Pu; Wang, XinHua

    2014-10-01

    Accurate knowledge of the neutron energy spectra is useful in basic research and applications. The overall procedure of measuring and unfolding the fast neutron energy spectra with BC501A liquid scintillation detector is described. The recoil proton spectrum of 241Am-Be neutrons was obtained experimentally. With the NRESP7 code, the response matrix of detector was simulated. Combining the recoil proton spectrum and response matrix, the unfolding of neutron spectra was performed by GRAVEL iterative algorithm. A MatLab program based on the GRAVEL method was developed. The continuous neutron spectrum of 241Am-Be source and monoenergetic neutron spectrum of D-T source have been unfolded successfully and are in good agreement with their standard reference spectra. The unfolded 241Am-Be spectrum are more accurate than the spectra unfolded by artificial neural networks in recent years.

  13. Simulation and Design of Multi-modulars Detector System of Gadolinium-Loaded Liquid Scintillator

    Institute of Scientific and Technical Information of China (English)

    HOU; Long; WANG; Zhao-hui; YU; Guo-liang; WANG; Qi; KANG; Guo-guo; SU; Xiao-bin; ZHANG; Xiao-peng; ZHANG; Kai

    2012-01-01

    <正>The gadolinium-loaded liquid scintillator has the superiority of high detecting efficiency, and it can be used to measure many kinds of nucleus. We improved this technique and construct a 4π liquid scintillator detecting systems which is composed by many liquid scintillators. By coupling with fission chamber, we form a novel research platform which can be used to measure the (n, 2n) and (n, 3n) cross sections of many nuclei.

  14. Borexino A real time liquid scintillator detector for low energy solar neutrino study

    CERN Document Server

    Miramonti, L

    2002-01-01

    Borexino is a large unsegmented calorimeter featuring 300 tons of liquid scintillator, contained in a 8.5 meter nylon vessel, viewed by 2200 PMTs. The main goal of Borexino is the study, in real time, of low energy solar neutrinos, and in particular, the monoenergetic neutrinos coming from $^7Be$, which is one of the missing links on the solar neutrino problem. The achievement of high radiopurity level, in the order of $10^{-16} g/g$ of U/Th equivalent, necessary to the detection of the low energy component of the solar neutrino flux, was proved in the Borexino prototype: the Counting Test Facility. The detector is located underground in the Laboratori Nazionali del Gran Sasso in the center of Italy at 3500 meter water equivalent depth. In this paper the science and technology of Borexino are reviewed and its main capabilities are presented.

  15. Development of a new neutron monitor using a boron-loaded organic liquid scintillation detector

    Energy Technology Data Exchange (ETDEWEB)

    Rasolonjatovo, A.H.D.; Shiomi, T.; Kim, E.; Nakamura, T. E-mail: nakamura@cyric.tohoku.ac.jp; Nunomiya, T.; Endo, A.; Yamaguchi, Y.; Yoshizawa, M

    2002-10-21

    A new type of neutron dose monitor was developed by using a 12.7 cm diameterx12.7 cm long boron-loaded organic liquid scintillation detector BC523A. This detector aims to have a response in the wide energy range of thermal energy to 100 MeV by using the H and C reactions to the fast neutrons of organic liquid and the {sup 10}B(n, {alpha}) reaction to thermalized neutrons in the liquid. The response functions of this detector were determined by the Monte Carlo simulation in the energy region from thermal energy to 100 MeV. Using these response functions, the spectrum-weighted dose function, G-function, to get the neutron dose from the light output spectrum of the detector was also determined by the unfolding technique. The calculated G-function was applied to determine the neutron dose in real neutron fields having energies ranging from thermal energy to several tens of MeV, where the light output spectra were measured with the BC523A detector. The thus-obtained ambient doses and effective doses show rather good agreement with the fluence-to-dose conversion factor given by ICRP 74. This detector will be useful as a wide-energy range neutron monitor.

  16. Development of a new neutron monitor using a boron-loaded organic liquid scintillation detector

    CERN Document Server

    Rasolonjatovo, A H D; Kim, E; Nakamura, T; Nunomiya, T; Endo, A; Yamaguchi, Y; Yoshizawa, M

    2002-01-01

    A new type of neutron dose monitor was developed by using a 12.7 cm diameterx12.7 cm long boron-loaded organic liquid scintillation detector BC523A. This detector aims to have a response in the wide energy range of thermal energy to 100 MeV by using the H and C reactions to the fast neutrons of organic liquid and the sup 1 sup 0 B(n, alpha) reaction to thermalized neutrons in the liquid. The response functions of this detector were determined by the Monte Carlo simulation in the energy region from thermal energy to 100 MeV. Using these response functions, the spectrum-weighted dose function, G-function, to get the neutron dose from the light output spectrum of the detector was also determined by the unfolding technique. The calculated G-function was applied to determine the neutron dose in real neutron fields having energies ranging from thermal energy to several tens of MeV, where the light output spectra were measured with the BC523A detector. The thus-obtained ambient doses and effective doses show rather ...

  17. Prompt directional detection of galactic supernova by combining large liquid scintillator neutrino detectors

    CERN Document Server

    Fischer, V; Lasserre, T; Volpe, C; Cribier, M; Durero, M; Gaffiot, J; Houdy, T; Letourneau, A; Mention, G; Pequignot, M; Sibille, V; Vivier, M

    2015-01-01

    Core-collapse supernovae produce an intense burst of electron antineutrinos in the few-tens-of-MeV range. Several Large Liquid Scintillator-based Detectors (LLSD) are currently operated worldwide, being very effective for low energy antineutrino detection through the Inverse Beta Decay (IBD) process. In this article, we develop a procedure for the prompt extraction of the supernova location by revisiting the details of IBD kinematics over the broad energy range of supernova neutrinos. Combining all current scintillator-based detector, we show that one can locate a canonical supernova at 10 kpc with an accuracy of 45 degrees (68% C.L.). After the addition of the next generation of scintillator-based detectors, the accuracy could reach 12 degrees (68% C.L.), therefore reaching the performances of the large water Cerenkov neutrino detectors. We also discuss a possible improvement of the SuperNova Early Warning System (SNEWS) inter-experiment network with the implementation of a directionality information in each...

  18. Neutron and photon spectrometry with liquid scintillation detectors in mixed fields

    CERN Document Server

    Klein, H

    2002-01-01

    Liquid scintillation detectors of type NE213 or BC501A are well suited and routinely used for spectrometry in mixed n-gamma-fields. Neutron- and photon-induced pulse height spectra may be simultaneously recorded making use of the n/gamma-discrimination capability based on pulse shape analysis. The light output functions for the detected secondary charged particles, i.e. electrons, positrons, protons and other charged reaction products, and the pulse height resolution function must carefully be determined. This can be done experimentally, in part via an iterative procedure by comparison with calculations. The response functions can then be reliably calculated by Monte Carlo simulations. Photon response functions calculated with the PHRESP code, which was developed on the basis of the EGS4+PRESTA program package, are in very good agreement with calibrations up to 17 MeV, both in shape and absolute scale. Similarly, neutron response functions calculated with the NRESP7 code well describe the pulse height spectra...

  19. Results of low energy background measurements with the Liquid Scintillation Detector (LSD) of the Mont Blanc Laboratory

    Science.gov (United States)

    Aglietta, M.; Badino, G.; Bologna, G. F.; Castagnoli, C.; Fulgione, W.; Galeotti, P.; Saavedra, O.; Trinchero, G. C.; Vernetto, S.; Dadykin, V. L.

    1985-01-01

    The 90 tons liquid scintillation detector (LSD) is fully running since October 1984, at a depth of 5,200 hg/sq cm of standard rock underground. The main goal is to search for neutrino bursts from collapsing stars. The experiment is very sensitive to detect low energy particles and has a very good signature to gamma-rays from (n,p) reaction which follows the upsilon e + p yields n + e sup + neutrino capture. The analysis of data is presented and the preliminary results on low energy measurements are discussed.

  20. Development of a liquid scintillator-based 3D detector for range measurements of spot-scanned proton beams

    Science.gov (United States)

    Darne, C. D.; Robertson, D.; Beddar, S.

    2017-05-01

    The goal of the present study is to develop a liquid scintillator-based 3D detector and investigate its performance for beam range measurements in real time. The detector design consists of a tank filled with water-equivalent liquid scintillator that scintillates in response to incident proton beams. Three scientific complementary metal-oxide semiconductor (sCMOS) cameras collect the resulting optical signals. Preliminary measurements have shown that the optical detection system can record light distribution profiles anywhere inside the tank with an average spatial resolution of 0.23 mm. By employing multiple cameras the system is capable of capturing high resolution 2D depth and beams-eye profiles of the delivered beam and can consequently localize the position of beam anywhere inside the tank. It is also shown that it is capable of accurately measuring proton beam range with no more than 0.3 mm difference from the nominal range. The detector system thus demonstrates its ability to perform fast, high-resolution, and precise beam range measurements in 3D.

  1. Study of digital pulse shape discrimination method for n-{\\gamma} separation of EJ-301 liquid scintillation detector

    CERN Document Server

    Wan, Bo; Chen, Liang; Ge, Honglin; Ma, Fei; Zhang, Hongbin; Ju, Yongqin; Zhang, Yanbin; Li, Yanyan; Xu, Xiaowei

    2015-01-01

    A digital pulse shape discrimination system based on a programmable module NI-5772 has been established and tested with EJ-301 liquid scintillation detector. The module was operated by means of running programs developed in LabVIEW with the sampling frequency up to 1.6GS/s. Standard gamma sources 22Na, 137Cs and 60Co were used to calibrate the EJ-301 liquid scintillation detector, and the gamma response function has been obtained. Digital algorithms for charge comparison method and zero-crossing method have been developed. The experimental results showed that both digital signal processing (DSP) algorithms could discriminate neutrons from gamma-rays. Moreover, the zero-crossing method shows better n-{\\gamma} discrimination at 80 keVee and lower, whereas the charge comparison method gives better results at higher thresholds. In addition, the figure-of-merit (FOM) of two different dimension detectors were extracted at 9 energy thresholds, and it was found that the smaller one presented a better n-{\\gamma} separ...

  2. Proton recoils in organic liquid scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Juergen [Technische Universitaet Muenchen, Physik Department E15, Garching (Germany); Collaboration: LENA Working Group

    2012-07-01

    In liquid-scintillator detectors like the LENA (Low Energy Neutrino Astronomy) project, understanding the nature of proton recoils is vital. First of all concerning the observation of the diffuse Supernova anti {nu}{sub e} background with the inverse beta decay (IBD). This signature can be mimicked by the thermalization and capture of a knockout neutron originating from inelastic NC interactions of atmospheric neutrinos on {sup 12}C. However, with the help of pulse shape discrimination between the neutron-induced proton recoils and the prompt positron signal from the IBD, this background might be reduced effectively. Furthermore, elastic {nu}-p scattering is an important channel for neutrinos from a galactic core-collapse SN. In order to reconstruct the initial neutrino energy, the energy-dependent quenching factor of proton recoils has to be known. Therefore, a neutron scattering experiment at the Maier-Leibnitz-Laboratorium in Garching has been set up in order to understand the response of proton recoils in organic liquid scintillator.

  3. Patient-specific quality assurance for spot scanning proton beams using a large-volume liquid scintillator detector

    Science.gov (United States)

    Robertson, D.; Beddar, S.

    2017-05-01

    A large-volume liquid scintillator detector was used to measure individual energy layers from a clinical prostate treatment plan on a scanning proton beam system. Lateral and beam’s-eye view images of the dose distribution were acquired with two CCD cameras facing adjacent sides of a scintillator tank. The measured dose images were compared with calculated dose distributions from a validated Monte Carlo model. The measured and calculated dose distributions showed good agreement, with the exception of the Bragg peak region of the lateral view, which exhibited ionization quenching. The beam’s-eye and lateral views achieved gamma analysis passing rates of 99.7% and 92.5%, respectively, using gamma criteria of 3%, 3 mm. Large-volume scintillator detectors show promise for quick and accurate measurements of patient treatment fields for scanning proton beam systems.

  4. Separating Double-Beta Decay Events from Solar Neutrino Interactions in a Kiloton-Scale Liquid Scintillator Detector By Fast Timing

    CERN Document Server

    Elagin, Andrey; Naranjo, Brian; Ouellet, Jonathan; Winslow, Lindley; Wongjirad, Taritree

    2016-01-01

    We present a technique for separating nuclear double beta decay ($\\beta\\beta$-decay) events from background neutrino interactions due to $^{8}$B decays in the sun. This background becomes dominant in a kiloton-scale liquid-scintillator detector deep underground and is usually considered as irreducible due to an overlap in deposited energy with the signal. However, electrons from 0$\

  5. Advanced Scintillator Detector Concept (ASDC): A Concept Paper on the Physics Potential of Water-Based Liquid Scintillator

    CERN Document Server

    Alonso, J R; Bergevin, M; Bernstein, A; Bignell, L; Blucher, E; Calaprice, F; Conrad, J M; Descamps, F B; Diwan, M V; Dwyer, D A; Dye, S T; Elagin, A; Feng, P; Grant, C; Grullon, S; Hans, S; Jaffe, D E; Kettell, S H; Klein, J R; Lande, K; Learned, J G; Luk, K B; Maricic, J; Marleau, P; Mastbaum, A; McDonough, W F; Oberauer, L; Gann, G D Orebi; Rosero, R; Rountree, S D; Sanchez, M C; Shaevitz, M H; Shokair, T M; Smy, M B; Strait, M; Svoboda, R; Tolich, N; Vagins, M R; van Bibber, K A; Viren, B; Vogelaar, R B; Wetstein, M J; Winslow, L; Wonsak, B; Worcester, E T; Wurm, M; Yeh, M; Zhang, C

    2014-01-01

    The recent development of Water-based Liquid Scintillator (WbLS), and the concurrent development of high-efficiency and high-precision-timing light sensors, has opened up the possibility for a new kind of large-scale detector capable of a very broad program of physics. The program would include determination of the neutrino mass hierarchy and observation of CP violation with long-baseline neutrinos, searches for proton decay, ultra-precise solar neutrino measurements, geo- and supernova neutrinos including diff?use supernova antineutrinos, and neutrinoless double beta decay. We outline here the basic requirements of the Advanced Scintillation Detector Concept (ASDC), which combines the use of WbLS, doping with a number of potential isotopes for a range of physics goals, high efficiency and ultra-fast timing photosensors, and a deep underground location. We are considering such a detector at the Long Baseline Neutrino Facility (LBNF) far site, where the ASDC could operate in conjunction with the liquid argon t...

  6. A high-rate sup 1 sup 0 B-loaded liquid scintillation detector for parity-violation studies in neutron resonances

    CERN Document Server

    Yen Yi Fen; Bolton, R D; Crawford, B E; Delheij, P P J; Hart, G W; Haseyama, T; Frankle, C M; Iinuma, M; Knudson, J N; Masaike, A; Masuda, Y; Matsuda, Y; Mitchell, G E; Penttilae, S I; Roberson, N R; Seestrom, S J; Sharapov, E I; Shimizu, H M; Smith, D A; Stephenson, S L; Szymanski, J J; Yoo, S H; Yuan, V W

    2000-01-01

    We have developed a large-area sup 1 sup 0 B-loaded liquid scintillation detector for parity-violation studies in neutron resonances with high instantaneous neutron fluxes from the LANSCE short-pulse spallation source. The detector has an efficiency of 95%, 85% and 71% at neutron energies of 10, 100 and 1000 eV, respectively. The neutron mean capture time in the detector is (416+-5) ns. We describe the detector and the current-mode signal processing system, that can handle neutron rates up to 500 MHz.

  7. Separating double-beta decay events from solar neutrino interactions in a kiloton-scale liquid scintillator detector by fast timing

    Science.gov (United States)

    Elagin, Andrey; Frisch, Henry J.; Naranjo, Brian; Ouellet, Jonathan; Winslow, Lindley; Wongjirad, Taritree

    2017-03-01

    We present a technique for separating nuclear double beta decay (ββ -decay) events from background neutrino interactions due to 8B decays in the sun. This background becomes dominant in a kiloton-scale liquid-scintillator detector deep underground and is usually considered as irreducible due to an overlap in deposited energy with the signal. However, electrons from 0 νββ -decay often exceed the Cherenkov threshold in liquid scintillator, producing photons that are prompt and correlated in direction with the initial electron direction. The use of large-area fast photodetectors allows some separation of these prompt photons from delayed isotropic scintillation light and, thus, the possibility of reconstructing the event topology. Using a simulation of a 6.5 m radius liquid scintillator detector with 100 ps resolution photodetectors, we show that a spherical harmonics analysis of early-arrival light can discriminate between 0 νββ -decay signal and 8B solar neutrino background events on a statistical basis. Good separation will require the development of a slow scintillator with a 5 ns risetime.

  8. Affect of Distinguishing of Neutron and Gamma for Liquid Scintillation Detector by Methods of Baseline Compensation

    Institute of Scientific and Technical Information of China (English)

    LI; Wei; LIU; Yi-na; LI; Chun-juan; WANG; Zhi-qiang; CHEN; Jun; LUO; Hai-long; ZHANG; Wei-hua; XU; Kun

    2015-01-01

    Most scintillation detectors are sensitive both for neutron and photon.Usually,there are photon in neutron fields which is coming from neutron source or reacting by neutron and materials around,so you must concern about the affect by photon which is below 10MeV.There will be a big effect for distinguishing

  9. Development of InP solid state detector and liquid scintillator containing metal complex for measurement of pp/7Be solar neutrinos and neutrinoless double beta decay

    Science.gov (United States)

    Fukuda, Yoshiyuki; Moriyama, Shigetaka

    2012-07-01

    A large volume solid state detector using a semi-insulating Indium Phosphide (InP) wafer have been developed for measurement of pp/7Be solar neutrinos. Basic performance such as the charge collection efficiency and the energy resolution were measured by 60% and 20%, respectively. In order to detect two gammas (115keV and 497keV) from neutrino capture, we have designed hybrid detector which consist InP detector and liquid xenon scintillator for IPNOS experiment. New InP detector with thin electrode (Cr 50Å- Au 50Å). For another possibility, an organic liquid scintillator containing indium complex and zirconium complex were studied for a measurement of low energy solar neutrinos and neutrinosless double beta decay, respectively. Benzonitrile was chosen as a solvent because of good solubility for the quinolinolato complexes (2 wt%) and of good light yield for the scintillation induced by gamma-ray irradiation. The photo-luminescence emission spectra of InQ3 and ZrQ4 in benzonitrile was measured and liquid scintillator cocktail using InQ3 and ZrQ4 (50mg) in benzonitrile solutions (20 mL) with secondary scintillators with PPO (100mg) and POPOP (10mg) was made. The energy spectra of incident gammas were measured, and they are first results of the gamma-ray energy spectra using luminescent of metal complexes.

  10. Measurements of high energy neutrons penetrated through iron shields using the Self-TOF detector and an NE213 organic liquid scintillator

    CERN Document Server

    Sasaki, M; Nunomiya, T; Nakamura, T; Fukumura, A; Takada, M

    2002-01-01

    Neutron energy spectra penetrated through iron shields were measured using the Self-TOF detector and an NE213 organic liquid scintillator which have been newly developed by our group at the Heavy-Ion Medical Accelerator in Chiba (HIMAC) of National Institute of Radiological Sciences (NIRS), Japan. Neutrons were generated by bombarding 400 MeV/nucleon C ion on a thick (stopping-length) copper target. The neutron spectra in the energy range from 20 to 800 MeV were obtained through the FORIST unfolding code with their response functions and compared with the MCNPX calculations combined with the LA150 cross section library. The neutron fluence measured by the NE213 detector was simulated by the track length estimator in the MCNPX, and evaluated the contribution of the room-scattered neutrons. The calculations are in fairly good agreement with the measurements. Neutron fluence attenuation lengths were obtained from the experimental results and the calculation.

  11. Monte Carlo simulation of prompt gamma-ray spectra from depleted uranium under D-T neutron irradiation and electron recoil spectra in a liquid scintillator detector

    CERN Document Server

    Qin, Jianguo; Liu, Rong; Zhu, Tonghua; Zhang, Xinwei; Ye, Bangjiao

    2015-01-01

    To overcome the problem of inefficient computing time and unreliable results in MCNP5 calculation, a two-step method is adopted to calculate the energy deposition of prompt gamma-rays in detectors for depleted uranium spherical shells under D-T neutrons irradiation. In the first step, the gamma-ray spectrum for energy below 7 MeV is calculated by MCNP5 code; secondly, the electron recoil spectrum in a BC501A liquid scintillator detector is simulated based on EGSnrc Monte Carlo Code with the gamma-ray spectrum from the first step as input. The comparison of calculated results with experimental ones shows that the simulations agree well with experiment in the energy region 0.4-3 MeV for the prompt gamma-ray spectrum and below 4 MeVee for the electron recoil spectrum. The reliability of the two-step method in this work is validated.

  12. Measurement of proton quenching factors and PSD-parameters in liquid scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, Vincenz; Winter, Juergen; Oberauer, Lothar; Meyer, Judith; Moellenberg, Randolph; Strauss, Raimund; Ciemniak, Christian; Wawoczny, Stephan; Scherzinger, Julius [Technische Universitaet Muenchen, Physik Department E15, Garching (Germany)

    2012-07-01

    In liquid-scintillator detectors like Borexino, Double Chooz and the LENA (Low Energy Neutrino Astronomy) project the inverse beta decay (IBD) is used to detect electron antineutrinos anti {nu}{sub e}. This causes a delayed coincidence signal reducing the background sources to those mimicking such a coincidence. Fast neutrons are one of the background sources by scattering off a proton followed by a capture on hydrogen or gadolinium. Therefore, it is vital to understand the nature of proton recoils in liquid scintillators. Using pulse shape discrimination (PSD) to distinguish the neutron-induced proton recoils from the prompt positron signal from the IBD this background might be reduced. Furthermore, elastic {nu}-p scattering is an important channel for neutrinos from a galactic core-collapse SN. In order to reconstruct the initial neutrino energy, the energy-dependent proton quenching factor has to be known. Therefore, a neutron scattering experiment at the Maier-Leibnitz-Laboratorium in Garching has been set up in order to understand the response of proton recoils in organic liquid scintillators.

  13. Quality study of the purified liquid scintillator

    Science.gov (United States)

    Konno, Y.; Nakajima, K.; Kibe, Y.

    2008-07-01

    We have been distilling the KamLAND liquid scintillator (LS) for the low energy solar neutrino observation. The distillation removes radioactive impurities from LS efficiently. We developed two types of high sensitivity radon detectors to monitor 222Rn contamination which causes a primary background source 210Pb. Their required sensitivity is several mBq/m3. The features and the measurement results of these detectors are presented. We also report the study of liquid scintillator properties after the distillation: attenuation length, light output and PPO density.

  14. The light-yield response of a NE-213 liquid-scintillator detector measured using 2 -- 6 MeV tagged neutrons

    CERN Document Server

    Scherzinger, J; Annand, J R M; Fissum, K G; Hall-Wilton, R; Kanaki, K; Lundin, M; Nilsson, B; Perrey, H; Rosborg, A; Svensson, H

    2016-01-01

    The response of a NE-213 liquid-scintillator detector has been measured using tagged neutrons from 2--6 MeV originating from an Am/Be neutron source. The neutron energies were determined using the time-of-flight technique. Pulse-shape discrimination was employed to discern between gamma-rays and neutrons. The behavior of both the fast (35 ns) and the combined fast and slow (475 ns) components of the neutron scintillation-light pulses were studied. Three different prescriptions were used to relate the neutron maximum energy-transfer edges to the corresponding recoil-proton scintillation-light yields, and the results were compared to simulations. Parametrizations which predict the fast or total light yield of the scintillation pulses were also tested. Our results agree with both existing data and existing parametrizations. We observe a clear sensitivity to the portion and length of the neutron scintillation-light pulse considered.

  15. Liquid Scintillation Counting

    OpenAIRE

    Carlsson, Sten

    1993-01-01

    In liquid scintillation counting (LSC) we use the process of luminescense to detect ionising radiation emit$ed from a radionuclide. Luminescense is emission of visible light of nonthermal origin. 1t was early found that certain organic molecules have luminescent properties and such molecules are used in LSC. Today LSC is the mostwidespread method to detect pure beta-ernitters like tritium and carbon-14. 1t has unique properties in its efficient counting geometry, deteetability and the lack of...

  16. Measurement of radon on Misasa district, Tottori pref. using the PICO-RAD detector and a liquid scintillation spectrometer. 3

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Taeko; Inagaki, Masayo; Morishima, Hiroshige; Tanaka, Yuki [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.; Nakanishi, Akihiro; Sasaki, Noriko; Mifune, Masaaki

    1996-12-01

    By means of a radon detecting device (Packard Pico-Rad System) using absorbed active charcoal and a liquid scintillation spectrometer, studies on environmental movements of radon and its decay nuclides on Misasa district in Tottori pref. were done continuously on last year. Its minimum detection limits of radon in the air are 1.7Bq/m{sup 3} and 0.43Bq/l in the water on counting time of 200 minutes. This method is able to measure conveniently and rapidly on sampling period for 24 hours. (1) Radon concentrations in the air at Misasa environs area on October and November, 1995 were ranged 7.7-59Bq/m{sup 3} in outdoor and 13-141Bq/m{sup 3} in indoor. On the results measured on Misasa area, {sup 222}Rn concentrations on Asahi district located southward from Misasa spa district and Takeda district along Tenjin stream are high, on Kojika district located east-southward from Misasa spa district and Mitoku district are low and outdoor {sup 222}Rn concentrations on Ningyo toge neighboring are low level with ranged 12-31Bq/m{sup 3}. Indoor {sup 222}Rn concentrations at Takeda district are about 4 times higher than Kojika district showed the lowest concentration and those of Kojika district are almost similar to those of Higashi Osaka. Indoor {sup 222}Rn concentration are higher than outdoor, the mean ratio of indoor to outdoor {sup 222}Rn concentration on a few sample of Takeda and Asahi districts (upper stream) are about 2 and those on the other district are shown in low tendency ranged 1-1.3. There are a few difference among some districts. (2) {sup 222}Rn concentration variations in a dwelling at Misasa spa district were observed from May to December 1995 in the time course. They are varied in range of 53-121Bq/m{sup 3} indoor, 9-50Bq/m{sup 3} outdoor and 48-188Bq/m{sup 3} in bathroom. (3) {sup 222}Rn concentration variations in water samples at Misasa spa district are 91-161Bq/l in hot spring, 2.3-10Bq/l in river water and 14-34Bq/l in well water from May to December 1995

  17. Monte Carlo simulation of the LENA detector system

    Energy Technology Data Exchange (ETDEWEB)

    Howard, C., E-mail: choward@unc.edu [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Iliadis, C.; Champagne, A.E. [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)

    2013-11-21

    Many nuclear astrophysics experiments use the singles energy spectrum to measure nuclear cross-sections. It has been shown in previous publications that the use of a high purity germanium (HPGe) detector and a NaI(Tl) annulus in coincidence can lower the background, allowing the measurement of smaller cross-sections. In our previous work, our simulation was only capable of determining both full-energy peak relative efficiencies. Here, we present work which extends our simulation so that we can predict absolute efficiencies, and both coincidence gate efficiencies. We first show that the full-energy peak and the total energy singles efficiency of our HPGe detector simulation agrees well with calibration data. We then present the full-energy peak and total energy efficiency for the NaI(Tl) annulus. Results are presented for our coincidence efficiencies, using three examples. These examples are a comparison to the decay of the 151 keV resonance in the {sup 18}O(p, γ){sup 19}F reaction, a {sup 22}Na point-like calibration source, and {sup 26}Al nuclei distributed in a meteorite fragment. In each case, we present a comparison of data to the simulation and show that, within our uncertainties, we can accurately simulate our measured intensities. -- Highlights: •We create a simulation of our HPGe detector and NaI annulus. •We compare our model to various calibration sources. •We compare energy gating using the simulation. •The simulation predict efficiencies as observed in the data.

  18. Liquid Scintillation Detectors for Gamma and Neutron Diagnostic at Textor and Results of Runaway and Sawtooth Oscillations

    NARCIS (Netherlands)

    Hoenen, F.; Graffmann, E.; Finken, K.H.; Barrenscheen, H. J.; Klein, H.; R. Jaspers,

    1994-01-01

    Time and energy resolved neutron and gamma measurements are performed at the TEXTOR tokamak with a fast liquid NE-213 scintillator. To distinguish between neutron and gamma (gamma)-ray induced events, pulse shape discrimination is used. To suppress scattered radiation, the detector is installed in w

  19. 直径30cm的等高圆柱形载钆液闪探测性能%Performance measurement of large volume ?30 cm×30 cm gadolinium-loaded liquid scintillator detector

    Institute of Scientific and Technical Information of China (English)

    朱传新; 牟云峰; 郑普

    2016-01-01

    Background: The gadolinium-loaded liquid scintillator detector is an important tool for particle detecting in the area of high energy physics and nuclear physics experiments.Purpose: In this work, a large-size?30cm×30cm gadolinium-loaded liquid scintillator detector has been developed for neutron measurement. Neutron gamma discrimination and distribution of neutron capture time of gadolinium-loaded liquid scintillator were main values of detecting performance.Methods: The n-gamma discrimination of the large-size gadolinium-loaded liquid scintillator detector has been studied using a252Cf spontaneous fission neutron source by zero-crossing method. It was observed that the neutron-gamma discrimination property of large-size gadolinium-loaded liquid scintillator detector was poor. n-gamma discrimination spectra of?30 cm×30 cm gadolinium-loaded liquid scintillator detector within1μs after the fission event were captured with coincidence method based on the start signal of fission fragment from252Cf fission chamber.Results: It was observed that the neutron-gamma discrimination property of large-size gadolinium-loaded liquid scintillator detector was also poor. The time distributions of neutron and gamma in the n-gamma discrimination spectra were measured by time-of-flight (TOF) technique and coincidence method. The peak time difference of neutron time distribution and gamma time distribution was 2 ns. The distribution of neutron capture time was measured for a?30 cm×30 cm gadolinium-loaded liquid scintillator detector with coincidence method based on the start signal of fission fragment from252Cf fission chamber. The main signals ofγ by neutron capture of?30 cm×30 cm gadolinium-loaded liquid scintillator detector were in about 30μs. The average time of neutron capture is 11μs. Conclusion: The neutron capture time property of homemade gadolinium-loaded liquid scintillator meets the experimental requirements. For the most signal of neutron and gamma within the

  20. Testing the MSW-LMA oscillation model with the LENA detector

    Energy Technology Data Exchange (ETDEWEB)

    Moellenberg, Randolph; Appel, Simon; Beischler, German; Hellgartner, Dominikus; Lewke, Timo; Meindl, Quirin; Oberauer, Lothar; Pfahler, Patrick; Prade, Ludwig; Tippmann, Marc; Winter, Juergen; Zimmer, Vincenz [Technische Universitaet Muenchen, Physik Department E15, James Franck Strasse, 85748 Garching (Germany); Collaboration: LAGUNA-LENA Working Group

    2013-07-01

    Up to now, the solar electron neutrino survival probability was only measured in energy regions, where the neutrino oscillations are either vacuum (E{sub ν}<1 MeV) or matter dominated (E{sub ν}>3.2 MeV). With the proposed 50 kt LENA detector, a high statistic measurement of the {sup 8}B-ν{sub e} flux down to ∝ 2 MeV is possible. Non standard neutrino interactions could influence P{sub ee} in the transition region between vacuum and matter dominated neutrino oscillations. Thus, a detailed GEANT4 based Monte Carlo study was performed, to analyze how precise the MSW-LMA solution can be tested with LENA. As there are several models for non standard neutrino interactions, a simple test model with constant P{sub ee} was used, to see how efficient this model can be discriminated from the MSW-LMA solution. Using the elastic neutrino electron scattering channel and the charged current reaction of ν{sub e} on {sup 13}C (ν{sub e} + {sup 13}C → {sup 13}N + e{sup -}), the constant P{sub ee} scenario can be excluded with 5 σ significance after 7 years measuring time.

  1. Detecting the upturn of the solar {sup 8}B neutrino spectrum with LENA

    Energy Technology Data Exchange (ETDEWEB)

    Möllenberg, R., E-mail: randolph.moellenberg@ph.tum.de [Excellence Cluster Universe, Technische Universität München, 85748 Garching (Germany); Feilitzsch, F. von; Hellgartner, D.; Oberauer, L.; Tippmann, M. [Physik Department, Technische Universität München, 85748 Garching (Germany); Winter, J.; Wurm, M. [Institut für Physik, Excellence Cluster PRISMA, Johannes Gutenberg Universität Mainz, 55128 Mainz (Germany); Zimmer, V. [Physik Department, Technische Universität München, 85748 Garching (Germany)

    2014-10-07

    LENA (Low Energy Neutrino Astronomy) has been proposed as a next generation 50 kt liquid scintillator detector. The large target mass allows a high precision measurement of the solar {sup 8}B neutrino spectrum, with an unprecedented energy threshold of 2 MeV. Hence, it can probe the MSW-LMA prediction for the electron neutrino survival probability in the transition region between vacuum and matter-dominated neutrino oscillations. Based on Monte Carlo simulations of the solar neutrino and the corresponding background spectra, it was found that the predicted upturn of the solar {sup 8}B neutrino spectrum can be detected with 5σ significance after 5 years.

  2. Detecting the Upturn of the Solar $^8$B Neutrino Spectrum with LENA

    CERN Document Server

    Möllenberg, Randolph; Hellgartner, Dominikus; Oberauer, Lothar; Tippmann, Marc; Winter, Jürgen; Wurm, Michael; Zimmer, Vincenz

    2014-01-01

    LENA (Low Energy Neutrino Astronomy) has been proposed as a next generation 50 kt liquid scintillator detector. The large target mass allows a high precision measurement of the solar $^8$B neutrino spectrum, with an unprecedented energy threshold of 2 MeV. Hence, it can probe the MSW-LMA prediction for the electron neutrino survival probability in the transition region between vacuum and matter-dominated neutrino oscillations. Based on Monte Carlo simulations of the solar neutrino and the corresponding background spectra, it was found that the predicted upturn of the solar $^8$B neutrino spectrum can be detected with 5 sigma significance after 5 y.

  3. Detecting the upturn of the solar 8B neutrino spectrum with LENA

    Directory of Open Access Journals (Sweden)

    R. Möllenberg

    2014-10-01

    Full Text Available LENA (Low Energy Neutrino Astronomy has been proposed as a next generation 50 kt liquid scintillator detector. The large target mass allows a high precision measurement of the solar 8B neutrino spectrum, with an unprecedented energy threshold of 2 MeV. Hence, it can probe the MSW-LMA prediction for the electron neutrino survival probability in the transition region between vacuum and matter-dominated neutrino oscillations. Based on Monte Carlo simulations of the solar neutrino and the corresponding background spectra, it was found that the predicted upturn of the solar 8B neutrino spectrum can be detected with 5σ significance after 5 years.

  4. Light propagation and fluorescence quantum yields in liquid scintillators

    Science.gov (United States)

    Buck, C.; Gramlich, B.; Wagner, S.

    2015-09-01

    For the simulation of the scintillation and Cherenkov light propagation in large liquid scintillator detectors a detailed knowledge about the absorption and emission spectra of the scintillator molecules is mandatory. Furthermore reemission probabilities and quantum yields of the scintillator components influence the light propagation inside the liquid. Absorption and emission properties are presented for liquid scintillators using 2,5-Diphenyloxazole (PPO) and 4-bis-(2-Methylstyryl)benzene (bis-MSB) as primary and secondary wavelength shifter. New measurements of the quantum yields for various aromatic molecules are shown.

  5. Light propagation and fluorescence quantum yields in liquid scintillators

    CERN Document Server

    Buck, C; Wagner, S

    2015-01-01

    For the simulation of the scintillation and Cherenkov light propagation in large liquid scintillator detectors a detailed knowledge about the absorption and emission spectra of the scintillator molecules is mandatory. Furthermore reemission probabilities and quantum yields of the scintillator components influence the light propagation inside the liquid. Absorption and emission properties are presented for liquid scintillators using 2,5-Diphenyloxazole (PPO) and 4-bis-(2-Methylstyryl)benzene (bis-MSB) as primary and secondary wavelength shifter. New measurements of the quantum yields for various aromatic molecules are shown.

  6. Large liquid-scintillator trackers for neutrino experiments

    CERN Document Server

    Benussi, L; D'Ambrosio, N; Déclais, Y; Dupraz, J P; Fabre, Jean-Paul; Fanti, V; Forton, E; Frekers, D; Frenkel, A; Girerd, C; Golovkin, S V; Grégoire, G; Harrison, K; Jonkmans, G; Jonsson, P; Katsanevas, S; Kreslo, I; Marteau, J; Martellotti, G; Martínez, S; Medvedkov, A M; Moret, G; Niwa, K; Novikov, V; Van Beek, G; Penso, G; Vasilchenko, V G; Vuilleumier, J L; Wilquet, G; Zucchelli, P; Kreslo, I E

    2002-01-01

    Results are given on tests of large particle trackers for the detection of neutrino interactions in long-baseline experiments. Module prototypes have been assembled using TiO$_2$-doped polycarbonate panels. These were subdivided into cells of $\\sim 1$~cm$^2$ cross section and 6~m length, filled with liquid scintillator. A wavelength-shifting fibre inserted in each cell captured a part of the scintillation light emitted when a cell was traversed by an ionizing particle. Two different fibre-readout systems have been tested: an optoelectronic chain comprising an image intensifier and an Electron Bombarded CCD (EBCCD); and a hybrid photodiode~(HPD). New, low-cost liquid scintillators have been investigated for applications in large underground detectors. Testbeam studies have been performed using a commercially available liquid scintillator. The number of detected photoelectrons for minimum-ionizing particles crossing a module at different distances from the fibre readout end was 6 to 12 with the EBCCD chain and ...

  7. In-Situ Measurement of Relative Attenuation Length of Gadolinium-Loaded Liquid Scintillator Using Source Data at RENO Experiment

    CERN Document Server

    Kim, H S; Choi, J H; Choi, W Q; Choi, Y; Jang, H I; Jang, J S; Joo, K K; Kim, B R; Kim, J Y; Kim, S B; Kim, W; Kwon, E; Lee, D H; Lim, I T; Pac, M Y; Park, I G; Park, J S; Park, R G; Seo, H; Seo, S H; Seon, Y G; Shin, C D; Yeo, I S; Yu, I

    2016-01-01

    We present an in-situ method of measuring the relative attenuation length of gadolinium-loaded liquid scintillator in the RENO detectors using radioactive source calibration data without requiring any PMT performance model. We observed the degradation of the attenuation length of the gadolinium-loaded liquid scintillator in the RENO detectors by ~50% over a period of about 4 years.

  8. Liquid scintillator production for the NOvA experiment

    CERN Document Server

    Mufson, S; Bower, C; Coan, T; Cooper, J; Corwin, L; Karty, J; Mason, P; Pla-Dalmau, A; Proudfoot, M

    2015-01-01

    The NOvA collaboration blended and delivered 8.8 kt (2.72M gal) of liquid scintillator to its detectors as its active detector medium. The composition of the scintillator was developed to meet the requirements of the experiment. The scintillator was shipped to the NOvA near and far detectors using dedicated stainless steel tanker trailers. A rigorous set of quality control procedures were put in place to assure that the liquid scintillator was blended to satisfy the transparency, light yield, and conductivity requirements. The incoming components, the blended scintillator, and the scintillator in the transport tanker trailers were all qualified with these procedures, which ensured that the NOvA scintillator was high quality and met its performance requirements.

  9. Measurement of radon in air using the PICO-RAD detector and a liquid scintillation spectrometer. 2. Misasa district, Tottori pref. on sampling of 1993

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Taeko; Inagaki, Masayo; Morishima, Hiroshige; Kawai, Hiroshi; Kondo, Sohei [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.; Morishita, Satoru; Kitamura, Naoya; Mifune, Masaaki

    1994-12-01

    A convenient radon detecting device for the purpose of estimating natural radiation exposure is described. The {alpha} radioactivity of its daughters originated from radon gas adsorbed in fine active carbon particles exposed to air is measured with a liquid scintillation spectrometer (Packard PICO-RAD system). Its detection limit is 1.7 Bq/m{sup 3} in air with an accuracy of about 10% on 200 minutes of counting time, and correction coefficient, the ratio of measured radon concentration to standard radon concentration (about 300 Bq/m{sup 3}) is 0.75 on the standard radon gas chamber of Power Reactor and Nuclear Fuel Development Corporation. Radon concentrations at Misasa hot springs in Tottori prefecture were measured using the PICO-RAD method on 1993. They were 128-3,600 Bq/m{sup 3} in a bath room, 25-45 Bq/m{sup 3} outdoors and 28-89 Bq/m{sup 3} indoors. (author).

  10. Temperature dependence of the light yield of the LAB-based and mesitylene-based liquid scintillators

    CERN Document Server

    DongMei, Xia; XiaoBo, Li; XiLei, Sun; YaYun, Ding; Li, Zhou; Jun, Cao; Wei, Hu; XingCheng, Ye; HaiTao, Chen; XueFeng, Ding; Bing, Du

    2014-01-01

    We studied the temperature dependence of the light yield of the linear alkyl benzene (LAB)-based and mesitylene-based liquid scintillators. The light yield increases by 23% for both liquid scintillators when the temperature is lowered from $26\\;^{\\circ}$C to $-40\\;^{\\circ }$C, correcting for the temperature response of the photomultiplier tube. The measurements help to understand the energy response of the liquid scintillator detectors. Especially, the next generation reactor neutrino experiments for neutrino mass hierarchy, such as the Jiangmen Underground Neutrino Observatory (JUNO), require very high energy resolution. As no apparent degradation on the liquid scintillator transparency was observed, lowering the operation temperature of the detector to $\\sim4\\;^\\circ$C will increase the photoelectron yield of the detector by 13%, combining the light yield increase of the liquid scintillator and the quantum efficiency increase of the photomultiplier tubes.

  11. Preliminary study of light yield dependence on LAB liquid scintillator composition

    OpenAIRE

    Ye, Xing-Chen; Yu, Bo-Xiang; Zhou, Xiang; Zhao, Li; Ding, Ya-yun; Jie, Quan-lin; Niu, Shun-Li; Liu, Meng-Chao; Ding, Xue-Feng; Zhang, Xuan; Zhou, Li; Fang, Jian; Chen, Hai-tao; HU, Wei; Yan, Jia-qing

    2015-01-01

    Liquid scintillator (LS) will be adopted as the detector material in JUNO (Jiangmen Underground Neutrino Observatory). The energy resolution requirement of JUNO is 3%, which has never previously been reached. To achieve this energy resolution, the light yield of liquid scintillator is an important factor. PPO (the fluor) and bis-MSB (the wavelength shifter) are the two main materials dissolved in LAB. To study the influence of these two materials on the transmission of scintillation photons i...

  12. Probing the Earth's Interior with the Low Energy Neutrino Astronomy Detector

    CERN Document Server

    Hochmuth, K A; Fields, B D; Marrodan, T; Oberauer, L; Potzel, W; Wurm, M; Hochmuth, Kathrin A.; Feilitzsch, Franz v.; Fields, Brian D.; Marrodan, Teresa; Oberauer, Lothar; Potzel, Walter; Wurm, Michael

    2005-01-01

    Recently a large volume liquid scintillation detector for Low Energy Neutrino Astronomy (LENA) has been proposed. With this experiment it will be possible to measure terrestrial antineutrinos originating from decays of the uranium and thorium chains to a very high precision. Moreover it can be shown that LENA opens up the possibility to measure the angular dependence of the geoneutrino rate with a precision of 26$^\\circ$ (half-cone aperture). Thus one is not only able to measure the total flux of neutrinos, but also to set stringent limits on different geological models, which give the distribution of radioactive elements throughout the earth.

  13. Light propagation in a large volume liquid scintillator

    CERN Document Server

    Alimonti, G; Balata, M; Bellini, G; Benziger, J; Bonetti, S; Caccianiga, B; Cadonati, L; Calaprice, F P; Cecchet, G; Chen, M; Darnton, N; De Bari, A; Deutsch, M; Elisei, F; Feilitzsch, F V; Galbiati, C; Gatti, F; Giammarchi, M G; Giugni, D; Goldbrunner, T; Golubchikov, A; Goretti, A; Hagner, T; Hartmann, F X; Hentig, R V; Heusser, G; Ianni, A; Johnson, M; Laubenstein, M; Lombardi, P; Magni, S; Malvezzi, S; Maneira, J; Manno, I; Manuzio, G; Masetti, F; Mazzucato, U; Meroni, E; Neff, M; Oberauer, L; Perotti, A; Raghavan, R S; Ranucci, G; Resconi, E; Salvo, C; Scardaoni, R; Schönert, S; Smirnov, O; Tartaglia, R; Testera, G; Vogelaar, R B; Vitale, S; Zaimidoroga, O A

    2000-01-01

    The fluorescence light propagation in a large volume detector based on organic liquid scintillators is discussed. In particular, the effects of the fluor radiative transport and solvent Rayleigh scattering are emphasized. These processes have been modelled by a ray-tracing Monte Carlo method and have been experimentally investigated in the Borexino prototype which was a 4.3 ton, 4 pi sensitive detector. The comparison between the model prediction and the experimental data shows a satisfactory agreement indicating that the main aspects of these processes are well understood. Some features of the experimental time response of the detector are still under study.

  14. Liquid scintillator production for the NOvA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mufson, S., E-mail: mufson@indiana.edu [Indiana University, Bloomington, IN 47405 (United States); Baugh, B.; Bower, C. [Indiana University, Bloomington, IN 47405 (United States); Coan, T.E. [Southern Methodist University, Dallas, TX 75275 (United States); Cooper, J. [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Corwin, L. [South Dakota School of Mines and Technology, Rapid City, SD 57701 (United States); Karty, J.A. [Indiana University, Bloomington, IN 47405 (United States); Mason, P. [University of Tennessee, Knoxville, TN 37916 (United States); Messier, M.D. [Indiana University, Bloomington, IN 47405 (United States); Pla-Dalmau, A. [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Proudfoot, M. [Renkert Oil, Morgantown, PA 19543 (United States)

    2015-11-01

    The NOvA collaboration blended and delivered 8.8 kt (2.72M gal) of liquid scintillator as the active detector medium to its near and far detectors. The composition of this scintillator was specifically developed to satisfy NOvA's performance requirements. A rigorous set of quality control procedures was put in place to verify that the incoming components and the blended scintillator met these requirements. The scintillator was blended commercially in Hammond, IN. The scintillator was shipped to the NOvA detectors using dedicated stainless steel tanker trailers cleaned to food grade.

  15. Optical Properties of Quantum-Dot-Doped Liquid Scintillators

    CERN Document Server

    Aberle, C; Weiss, S; Winslow, L

    2013-01-01

    Semiconductor nanoparticles (quantum dots) were studied in the context of liquid scintillator development for upcoming neutrino experiments. The unique optical and chemical properties of quantum dots are particularly promising for the use in neutrinoless double beta decay experiments. Liquid scintillators for large scale neutrino detectors have to meet specific requirements which are reviewed, highlighting the peculiarities of quantum-dot-doping. In this paper, we report results on laboratory-scale measurements of the attenuation length and the fluorescence properties of three commercial quantum dot samples. The results include absorbance and emission stability measurements, improvement in transparency due to filtering of the quantum dot samples, precipitation tests to isolate the quantum dots from solution and energy transfer studies with quantum dots and the fluorophore PPO.

  16. Optical properties of quantum-dot-doped liquid scintillators

    Science.gov (United States)

    Aberle, C.; Li, J. J.; Weiss, S.; Winslow, L.

    2013-10-01

    Semiconductor nanoparticles (quantum dots) were studied in the context of liquid scintillator development for upcoming neutrino experiments. The unique optical and chemical properties of quantum dots are particularly promising for the use in neutrinoless double-beta decay experiments. Liquid scintillators for large scale neutrino detectors have to meet specific requirements which are reviewed, highlighting the peculiarities of quantum-dot-doping. In this paper, we report results on laboratory-scale measurements of the attenuation length and the fluorescence properties of three commercial quantum dot samples. The results include absorbance and emission stability measurements, improvement in transparency due to filtering of the quantum dot samples, precipitation tests to isolate the quantum dots from solution and energy transfer studies with quantum dots and the fluorophore PPO.

  17. Characterization and Modeling of a Water-based Liquid Scintillator

    CERN Document Server

    Bignell, Lindsey J; Diwan, Milind V; Hans, Sunej; Jaffe, David E; Kettell, Steven; Rosero, Richard; Themann, Harry W; Viren, Brett; Worcester, Elizabeth; Yeh, Minfang; Zhang, Chao

    2015-01-01

    We have characterised Water-based Liquid Scintillator (WbLS) using low energy protons, UV-VIS absorbance, and fluorescence spectroscopy. We have also developed and validated a simulation model that describes the behaviour of WbLS in our detector configurations for proton beam energies of 2 GeV, 475 MeV, and 210 MeV and for two WbLS compositions. Our results have enabled us to estimate the light yield and ionisation quenching of WbLS, as well as to understand the influence of the wavelength shifting of Cerenkov light on our measurements. These results are relevant to the suitability of water-based liquid scintillator materials for next generation intensity frontier experiments.

  18. Study of n-γ discrimination for 0.4-1 MeV neutrons using the zero-crossing method with a BC501A liquid scintillation detector

    Institute of Scientific and Technical Information of China (English)

    CHEN Yong-Hao; LEI Jia-Rong; ZHANG Xiao-Dong; AN Li; ZHENG Pu; WANG Xin-Hua; ZHU Chuan-Xin

    2013-01-01

    An experimental system aimed at n-γ discrimination using the zero-crossing method with a φ3"× 2"BC501A liquid scintillation detector was established and tested with an Am-Be neutron source.Two-dimensional plots of energy versus zero-crossing time were obtained.The quality of n-γdiscrimination was checked by the figure-of-merit (FOM),the neutron peak-to-valley ratio,and the proportion of leaked neutrons over all neutron events.The performance of n-γ discrimination in terms of FOM was compared with previous work done by other groups.The n-γ discrimination in four different energy regions with an interval of 0.1 MeV between 0.3 MeV and 0.7 MeV was studied,and the results indicate that the n-γ discrimination threshold can go down to 0.4 MeV.

  19. CdZnTe room-temperature semiconductor operation in liquid scintillator

    CERN Document Server

    Stewart, D Y

    2008-01-01

    We demonstrate the first operation of CdZnTe room-temperature detectors in a liquid scintillator environment. This work follows conceptually the Heusser-type detector method of operating HPGe detectors in liquid nitrogen and liquid argon but instead for a far more practical room-temperature ensemble with the aim of achieving ultra-low background levels for radiation detection.

  20. Radiopure Metal-Loaded Liquid Scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Rosero, Richard [Brookhaven National Lab. (BNL), Upton, NY (United States). Chemistry Dept.; Yeh, Minfang [Brookhaven National Lab. (BNL), Upton, NY (United States). Chemistry Dept.

    2015-03-18

    Metal-loaded liquid scintillator plays a key role in particle and nuclear physics experiments. The applications of metal ions in various neutrino experiments and the purification methods for different scintillator components are discussed in this paper.

  1. Effect Factors of Liquid Scintillation Analysis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Over the past decades, the liquid scintillation analysis (LSA) technique remains one of the most popular experimental tools used for the quantitative analysis of radionuclide, especially low-energy β

  2. Measuring the 14C content in liquid scintillators

    Science.gov (United States)

    Enqvist, T.; Barabanov, I. R.; Bezrukov, L. B.; Gangapshev, A. M.; Gavrilyuk, Y. M.; Grishina, V. Yu; Gurentsov, V. I.; Hissa, J.; Joutsenvaara, J.; Kazalov, V. V.; Krokhaleva, S.; Kutuniva, J.; Kuusiniemi, P.; Kuzminov, V. V.; Kurlovich, A. S.; Loo, K.; Lubsandorzhiev, B. K.; Lubsandorzhiev, S.; Morgalyuk, V. P.; Novikova, G. Y.; Pshukov, A. M.; Sinev, V. V.; Słupecki, M.; Trzaska, W. H.; Umerov, Sh I.; Veresnikova, A. V.; Virkajärvi, A.; Yanovich, Y. A.; Zavarzina, V. P.

    2016-05-01

    We are going to perform a series of measurements where the 14C/12 C ratio will be measured from several liquid scintillator samples with a dedicated setup. The setup is designed with the aim of measuring ratios smaller than 10-18. Measurements take place in two underground laboratories: in the Baksan Neutrino Observatory, Russia and in the Pyhäsalmi mine, Finland. In Baksan the measurements started in 2015 and in Pyhäsalmi they start in the beginning of 2015. In order to fully understand the operation of the setup and its background contributions a development of simulation packages has also been started. Low-energy neutrino detection with a liquid scintillator requires that the intrinsic 14C content in the liquid is extremely low. In the Borexino CTF detector at Gran Sasso, Italy the 14C/12C ratio of 2 × 10-18 has been achieved being the lowest 14C concentration ever measured. In principle, the older the oil or gas source that the liquid scintillator is derived of and the deeper it situates, the smaller the 14C/12C ratio is supposed to be. This, however, is not generally the case, and the ratio is probably determined by the U and Th content of the local environment.

  3. Optical Design Considerations for Efficient Light Collection from Liquid Scintillation Counters

    Energy Technology Data Exchange (ETDEWEB)

    Bernacki, Bruce E.; Douglas, Matthew; Erchinger, Jennifer L.; Fuller, Erin S.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Orrell, John L.; Panisko, Mark E.; Warren, Glen A.; Wright, Michael E.

    2015-01-01

    Liquid scintillation counters measure charged particle-emitting radioactive isotopes and are used for environmental studies, nuclear chemistry, and life science. Alpha and beta emissions arising from the material under study interact with the scintillation cocktail to produce light. The prototypical liquid scintillation counter employs low-level photon-counting detectors to measure the arrival of the scintillation light produced as a result of the dissolved material under study interacting with the scintillation cocktail. For reliable operation the counting instrument must convey the scintillation light to the detectors efficiently and predictably. Current best practices employ the use of two or more detectors for coincidence processing to discriminate true scintillation events from background events due to instrumental effects such as photomultiplier tube dark rates, tube flashing, or other light emission not generated in the scintillation cocktail vial. In low background liquid scintillation counters additional attention is paid to shielding the scintillation cocktail from naturally occurring radioactive material (NORM) present in the laboratory and within the instruments construction materials. Low background design is generally at odds with optimal light collection. This study presents the evolution of a light collection design for liquid scintillation counting in a low background shield. The basic approach to achieve both good light collection and a low background measurement is described. The baseline signals arising from the scintillation vial are modeled and methods to efficiently collect scintillation light are presented as part of the development of a customized low-background, high sensitivity liquid scintillation counting system.

  4. Characteristics of Gd-loaded liquid scintillators BC521 and BC525

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, K. [Variable Energy Cyclotron Centre, 1-AF, Bidhannagar, Kolkata 700 064 (India)], E-mail: kaushik@veccal.ernet.in; Kundu, S.; Mukhopadhyay, S.; Rana, T.K.; Bhattacharya, S.; Bhattacharya, C.; Banerjee, S.R.; Ghosh, T.K.; Mukherjee, G.; Bandyopadhyay, T.; Dey, A.; Meena, J.K.; Mukhopadhyay, P.; Gupta, D.; Pal, S.; Pandit, D. [Variable Energy Cyclotron Centre, 1-AF, Bidhannagar, Kolkata 700 064 (India); Bhattacharya, S. [Department of Physics, Darjeeling Government College, Darjeeling 734 101, West Bengal (India)

    2007-10-11

    Characteristic features of neutron detection properties of the loaded liquid scintillators, i.e., capture time distribution, pulse shape discrimination, and time resolution have been studied for two Gd-loaded liquid scintillators, BC521 and BC525. A new technique to measure the capture time distribution with a small size neutron detector (capacity 7.3 l) in combination with BaF{sub 2} {gamma}-ray detectors has been demonstrated. The measured capture time distributions were in good agreement with the results obtained by Monte Carlo simulation using the computer code DENIS.

  5. Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection

    CERN Document Server

    Aberle, C; Gramlich, B; Hartmann, F X; Lindner, M; Schönert, S; Schwan, U; Wagner, S; Watanabe, H

    2011-01-01

    Over the course of several decades organic liquid scintillators form the basis for successful neutrino detectors. For electron antineutrino detection at nuclear reactor plants, gadolinium loaded liquid scintillators provide efficient background suppression. In the Double Chooz reactor antineutrino experiment a newly developed gadolinium-loaded scintillator is utilized for the first time. Its large scale production and characterization as well as the creation of an additional metalfree scintillator are presented. Both organic liquids are used in the inner part of the Double Chooz detectors.

  6. Liquid scintillators and liquefied rare gases for particle detectors. Background-determination in Double Chooz and scintillation properties of liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Martin Alexander

    2012-11-27

    Evidence for physics beyond the well-established standard model of particle physics is found in the sector of neutrino physics, in particular in neutrino oscillations, and in experimental hints requiring the presence of Dark Matter. Neutrino oscillations demand the neutrinos to be massive and at least four additional parameters, three mixing angles and one phase, are introduced. A non-vanishing value for the third mixing angle, {theta}{sub 13}, has only recently been found, amongst others by the reactor antineutrino disappearance experiment Double Chooz. This experiment detects anti {nu}{sub e}'s by means of the Inverse Beta Decay (IBD), which has a clear signature that can very effectively be discriminated from most of the background. However, some background still survives the selection cuts applied to the data, partly induced by radioactivity. In order to determine the amount of radioimpurities in the detector, germanium spectroscopy measurements and neutron activation analyses have been carried out for various parts of the Double Chooz far detector. A dedicated Monte-Carlo simulation was performed to obtain the singles event rate induced by the identified radioimpurities in the fiducial volume of Double Chooz. In the present thesis, parts from the outer detector systems, as well as components of the inner detector liquids were measured. In sum, a singles rate of less than 0.35 Hz above the antineutrino detection threshold of 0.7 MeV has been found. This is by far below the design goal of Double Chooz of {proportional_to} 20 Hz. The analysis of bismuth-polonium (BiPo) coincidences in the first Double Chooz data allows to directly determine the number of decays from the U- and the Th-decay chain in the active detector parts. Assuming radioactive equilibrium, concentrations of (1.71{+-}0.08).10{sup -14}(g)/(g) for uranium and (8.16{+-}0.49).10{sup -14}(g)/(g) for thorium have been found, which are also well below the design goal of Double Chooz (2.10{sup -13

  7. The efficiency study of different purification methods for liquid scintillator

    CERN Document Server

    Hu, Wei; Yu, Boxiang; Zhang, Xuan; Zhou, Li; Cai, Xiao; Sun, Lijun

    2016-01-01

    JUNO is an experiment aimed at detecting neutrino mass hierarchy. The innermost part of the JUNO detector is formed by 20,000 tons of liquid scintillator which should have very low level of radioactive materials, such as 238U, 232Th, and 40K. Since the radioactive level of raw LAB(the solvent of LS)cannot reach so stringent requirements of JUNO, the purification for LAB plays an extremely important role in LS production. This article studies the efficiency of several different purification methods for LS, like distillation, water extraction and Al2O3 purification.

  8. Design and Construction of the First Prototype of Liquid Scintillator Detector for Fast Beam Loss Monitor(FBLM) System%快响应束流损失监控(FBLM)系统液闪探测器初样的研制

    Institute of Scientific and Technical Information of China (English)

    韩晨霞; 陈昌; 田建民; 赵中亮; 徐美杭; 李公平; 陈元柏; 徐韬光; 赵海泉

    2011-01-01

    给出快响应束流损失监控(Fast Beam Lost Monitor,FBLM)系统的液体闪烁体探测器初样的研制.在高频四极加速器(Radio Frequency Quadrupole,RFQ)实验装置上的测试表明,液闪探测器能给出宽度为500 μs 束流宏脉冲结构,能逐个显示出宏脉冲内490 ns的束流切束脉冲.液闪输出信号脉冲较490 ns束流切束脉冲延迟约70 ns.液闪型FBLM输出的信号幅度大于塑闪型.液闪探测器初样的成功研制,为其性能进一步改进提高,打下了良好的基础.%Design and constmction of the first prototype of liquid scintillator detector for fast beam loss monitor ( FBLM ) system are given. A beam chopping device can remove a 490 ns section of beam at approximately 1 MHz repetition rate within a 500 μs macro beam pulse - width. The liquid scintillator displays the measured beam - pulse structure after the beam chopper. Through RFQ special beam structure, the response time of FBLM is measured. The response time of FBLM is about nano second. The signal amplitude from liquid scintillator is larger than plastic scintillator. All of these give us good experiences for the futher improvement of liquid seintillator detector design and construction. According to the measurement data. liquid seintillator is suggested as the detector of FBLM system.

  9. Performance of Water-Based Liquid Scintillator: An Independent Analysis

    Directory of Open Access Journals (Sweden)

    D. Beznosko

    2014-01-01

    Full Text Available The water-based liquid scintillator (WbLS is a new material currently under development. It is based on the idea of dissolving the organic scintillator in water using special surfactants. This material strives to achieve the novel detection techniques by combining the Cerenkov rings and scintillation light, as well as the total cost reduction compared to pure liquid scintillator (LS. The independent light yield measurement analysis for the light yield measurements using three different proton beam energies (210 MeV, 475 MeV, and 2000 MeV for water, two different WbLS formulations (0.4% and 0.99%, and pure LS conducted at Brookhaven National Laboratory, USA, is presented. The results show that a goal of ~100 optical photons/MeV, indicated by the simulation to be an optimal light yield for observing both the Cerenkov ring and the scintillation light from the proton decay in a large water detector, has been achieved.

  10. Development of a reference liquid scintillation cocktail

    CSIR Research Space (South Africa)

    Van Wyn Gaardt, WM

    2006-02-01

    Full Text Available of a scintillator dissolved in an organic solvent. The so-called scintillator solute is a material which emits a weak light flash or scintillation upon interaction with a certain quanta of radiation – the intensity of this scintillation being a... to prepare preliminary liquid scintillation cocktails. Figure 3: Maximum deviations observed between repeat measurements of the same source, displayed in red for Ultima Gold, green for XP, yellow for XI and blue for XPI. Figure 4: The counting...

  11. Measurement of Radiation Damage of Water-based Liquid Scintillator and Liquid Scintillator

    CERN Document Server

    Bignell, Lindsey J; Hans, Sunej; Jaffe, David E; Rosero, Richard; Vigdor, Steven; Viren, Brett; Worcester, Elizabeth; Yeh, Minfang; Zhang, Chao

    2015-01-01

    Liquid scintillating phantoms have been proposed as a means to perform real-time 3D dosimetry for proton therapy treatment plan verification. We have studied what effect radiation damage to the scintillator will have upon this application. We have performed measurements of the degradation of the light yield and optical attenuation length of liquid scintillator and water-based liquid scintillator after irradiation by 201 MeV proton beams that deposited doses of approximately 52 Gy, 300 Gy, and 800 Gy in the scintillator. Liquid scintillator and water-based liquid scintillator (composed of $5\\%$ scintillating phase) exhibit light yield reductions of $1.74 \\pm 0.55 \\%$ and $1.31 \\pm 0.59 \\%$ after $\\approx$ 800 Gy of proton dose, respectively. Whilst some increased optical attenuation was observed in the irradiated samples, the measured reduction to the light yield is also due to damage to the scintillation light production. Based on our results and conservative estimates of the expected dose in a clinical conte...

  12. Solar neutrino interactions with liquid scintillators used for double beta decay experiments

    CERN Document Server

    Ejiri, Hiroyasu

    2016-01-01

    Solar neutrinos interact with double beta decay detectors (DBD) and hence will contribute to backgrounds (BG) for DBD experiments. Background contributions due to solar neutrinos are evaluated for their interactions with atomic electrons and nuclei in liquid scintillation detectors used for DBD experiments. They are shown to be serious backgrounds for high sensitivity DBD experiments to search for the Majorana neutrino masses in the inverted and normal hierarchy regions.

  13. Solar neutrino interactions with liquid scintillators used for double beta-decay experiments

    Science.gov (United States)

    Ejiri, Hiroyasu; Zuber, Kai

    2016-08-01

    Solar neutrinos interact within double-beta-decay (DBD) detectors and hence will contribute to backgrounds (BGs) for DBD experiments. Background contributions due to solar neutrinos are evaluated for their interactions with atomic electrons and nuclei in liquid scintillation detectors used for DBD experiments. They are shown to be serious BGs for high-sensitivity DBD experiments to search for the Majorana neutrino masses in the inverted and normal hierarchy regions.

  14. Development of new Polysiloxane Based Liquid Scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Palma, M.; Quaranta, A. [Department of Industrial Engineering, University of Trento,Via Sommarive, 9, 38123 Trento (Italy); INFN, Laboratori Nazionali di Legnaro,Viale dell' Universita, 2, 35020 Legnaro - Padova (Italy); Gramegna, F.; Marchi, T.; Cinausero, M. [INFN, Laboratori Nazionali di Legnaro,Viale dell' Universita, 2, 35020 Legnaro - Padova (Italy); Carturan, S.; Collazuol, G.; Checchia, C. [INFN, Laboratori Nazionali di Legnaro,Viale dell' Universita, 2, 35020 Legnaro - Padova (Italy); Department of Physics and Astronomy, University of Padova, Via Marzolo, 8, 35131 Padova (Italy); Degerlier, M. [Department of Physics, Nevsehir Haci Bektas Veli University, Science and Art Faculty, 50300 Nevsehir (Turkey)

    2015-07-01

    In the last decade, attention toward neutron detection has been growing in the scientific community, driven by new requirements in different fields of application ranging from homeland security to medical and material analysis, from research physics, to nuclear energy production. So far neutron detection, with particular attention to fast neutrons, has been mainly based on organic liquid scintillators, owing to their good efficiency and pulse shape discrimination (PSD) capability. Most of these liquids have however some main drawbacks given by toxicity, flammability, volatility and sensitivity to dissolved oxygen that limits the duration and the quality of their performances with worse handiness and increased costs. Phenyl-substituted polysiloxanes could address most of these issues, being characterized by low toxicity, low volatility and low flammability. Their optical properties can be tailored by changing the phenyl distribution and concentration thus allowing to increase the solubility of organic dyes, to modify the fluorescence spectra and to vary the refractive index of the medium. Furthermore, polysiloxanes have been recently exploited for the production of plastic scintillators with very good chemical and thermal stability and very good radiation hardness and the development of polysiloxane liquid scintillators could allow to combine these interesting properties with the supremacy of liquid scintillators as regarding PSD over plastics. For these reasons, the properties of several phenyl-substituted polysiloxane with different phenyl amounts and different viscosities have been investigated, with particular attention to the scintillation response and the pulse shape discrimination capability, and the results of the investigation are reported in this work. More in details, the scintillation light yield towards gamma rays ({sup 60}Co and {sup 137}Cs) of several polysiloxane liquids has been analyzed and compared with the light yield of a commercial non

  15. Radon measurement using a liquid scintillation spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Taeko; Morishima, Hiroshige; Kawai, Hiroshi; Kondo, Sohei (Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.); Mifune, Masaki; Konishi, Masanobu; Shirai, Chiaki

    1992-12-01

    A convenient radon detecting device for the purpose of estimating natural radiation exposure is described. The [alpha] radioactivity of radon gas absorbed in fine active carbon particles exposed to air is measured with a liquid scintillation spectrometer (Packard-PICO-RAD system). Its detection limits are 2mBq/l in air and 0.5 Bq/l in water with an accuracy of about 10 %. Radon concentrations at Misasa hot springs in Tottori prefecture were measured using this method. They were 0.16 [approx] 7.7 Bq/l in a bath room and 0.057 [approx] 0.36 Bq/l outdoors. Radon concentrations of the hot springs were 82 [approx] 1,700 Bq/l. (author).

  16. Alpha counting and spectrometry using liquid scintillation methods

    Energy Technology Data Exchange (ETDEWEB)

    McDowell, W J

    1986-01-01

    The material in this report is intended to be a practical introduction and guide to the use of liquid scintillation for alpha counting and spectrometry. Other works devoted to the development of the theory of liquid scintillation exist and a minimum of such material is repeated here. Much remains to be learned and many improvements remain to be made in the use of liquid scintillation for alpha counting and spectrometry. It is hoped that this modest work will encourage others to continue development in the field.

  17. Preliminary study of light yield dependence on LAB liquid scintillator composition

    CERN Document Server

    Ye, Xing-Chen; Zhou, Xiang; Zhao, Li; Ding, Ya-Yun; Jie, Quan-Lin; Niu, Shun-Li; Liu, Meng-Chao; Ding, Xue-Feng; Zhang, Xuan; Zhou, Li; Fang, Jian; Chen, Hai-Tao; Hu, Wei; Yan, Jia-Qing; Zhao, Hang; Hong, Dao-Jin

    2015-01-01

    Liquid scintillator (LS) will be adopted as the detector material in JUNO (Jiangmen Underground Neutrino Observatory). The energy resolution requirement of JUNO is 3%, which has never previously been reached. To achieve this energy resolution, the light yield of liquid scintillator is an important factor. PPO (the fluor) and bis-MSB (the wavelength shifter) are the two main materials dissolved in LAB. To study the influence of these two materials on the transmission of scintillation photons in LS, 25 and 12 cm-long quartz vessels were used in a light yield experiment. LS samples with different concentration of PPO and bis-MSB were tested. At these lengths, the light yield growth is not obvious when the concentration of PPO is higher than 4 g/L. The influence from bis-MSB becomes insignificant when its concentration is higher than 8 mg/L. This result could provide some useful suggestions for the JUNO LS.

  18. Fine grained electromagnetic lead-liquid scintillator calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, L.; Fluri, L.; Perrin, D.; Vuilleumier, J.M. (Neuchatel Univ. (Switzerland)); Bonesini, M.; Cavalli, D.; Costa, G.; Mandelli, L.; Mazzanti, M.; Tamborini, M. (Istituto Nazionale di Fisica Nucleare, Milan (Italy))

    1983-02-15

    A new technique using liquid scintillator contained in teflon tubes to build a low cost high spatial resolution electromagnetic sampling calorimeter is described. Test results and comparison with a Monte Carlo simulation are presented.

  19. Oxygen quenching in LAB based liquid scintillator and nitrogen bubbling

    CERN Document Server

    Hua-Lin, Xiao

    2009-01-01

    Oxygen quenching effect in Linear Alkl Benzne (LAB) based liquid scintillator (LAB+3g/L POPOP+ 15 mg Bis--MSB) was studied by measuring the light yield as the function of nitrogen bubbling time. it shows that the light yield of fully purged liquid scintillator would increase of nearly 11% in room temperature and room atmosphere pressure. A simple model of nitrogen bubbling was built to describe the relationship between relative light yield (oxygen quenching factor) and bubbling time.

  20. Recent Developments In Fast Neutron Detection And Multiplicity Counting With Verification With Liquid Scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Nakae, L; Chapline, G; Glenn, A; Kerr, P; Kim, K; Ouedraogo, S; Prasad, M; Sheets, S; Snyderman, N; Verbeke, J; Wurtz, R

    2011-09-30

    For many years at LLNL, we have been developing time-correlated neutron detection techniques and algorithms for applications such as Arms Control, Threat Detection and Nuclear Material Assay. Many of our techniques have been developed specifically for the relatively low efficiency (a few percent) attainable by detector systems limited to man-portability. Historically, we used thermal neutron detectors (mainly {sup 3}He), taking advantage of the high thermal neutron interaction cross-sections. More recently, we have been investigating the use of fast neutron detection with liquid scintillators, inorganic crystals, and in the near future, pulse-shape discriminating plastics which respond over 1000 times faster (nanoseconds versus tens of microseconds) than thermal neutron detectors. Fast neutron detection offers considerable advantages, since the inherent nanosecond production time-scales of spontaneous fission and neutron-induced fission are preserved and measured instead of being lost by thermalization required for thermal neutron detectors. We are now applying fast neutron technology to the safeguards regime in the form of fast portable digital electronics as well as faster and less hazardous scintillator formulations. Faster detector response times and sensitivity to neutron momentum show promise for measuring, differentiating, and assaying samples that have modest to very high count rates, as well as mixed fission sources like Cm and Pu. We report on measured results with our existing liquid scintillator array, and progress on the design of a nuclear material assay system that incorporates fast neutron detection, including the surprising result that fast liquid scintillator detectors become competitive and even surpass the precision of {sup 3}He-based counters measuring correlated pairs in modest (kg) samples of plutonium.

  1. Recent Developments in Fast Neutron Detection and Multiplicity Counting with Liquid Scintillator

    Science.gov (United States)

    Nakae, L. F.; Chapline, G. F.; Glenn, A. M.; Kerr, P. L.; Kim, K. S.; Ouedraogo, S. A.; Prasad, M. K.; Sheets, S. A.; Snyderman, N. J.; Verbeke, J. M.; Wurtz, R. E.

    2011-12-01

    For many years, LLNL researchers have been developing time-correlated neutron detection techniques and algorithms for applications such as Arms Control, Threat Detection and Nuclear Material Assay. Many of the techniques have been developed specifically for the relatively low efficiency (a few percent) attainable by detector systems limited to man-portability. Historically, thermal neutron detectors (mainly 3He) were used, taking advantage of the high thermal neutron interaction cross sections. More recently, we have been investigating the use of fast neutron detection with liquid scintillators, inorganic crystals, and in the near future, pulse-shape discriminating plastics that respond over 1000 times faster (ns versus tens of μs) than thermal neutron detectors. Fast neutron detection offers considerable advantages since the inherent ns production timescales of spontaneous fission and neutron-induced fission are preserved and measured instead of being lost by thermalization required for thermal neutron detectors. We are now applying fast neutron technology to the safeguards regime in the form of fast portable digital electronics as well as faster and less hazardous scintillator formulations. Faster detector response times and sensitivity to neutron momentum show promise for measuring, differentiating, and assaying samples that have modest to very high count rates, as well as mixed fission sources like Cm and Pu. We report on measured results with our existing liquid scintillator array and progress on the design of a nuclear material assay system that incorporates fast neutron detection, including the surprising result that fast liquid scintillator detectors become competitive and even surpass the precision of 3He-based counters measuring correlated pairs in modest (kg) samples of plutonium.

  2. Liquid Scintillation High Resolution Spectral Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    2010-08-06

    The CIEMAT/NIST and the TDCR methods in liquid scintillation counting are based on the determination of the efficiency for total counting. This paper tries to expand these methods analysing the pulse-height spectrum of radionuclides. To reach this objective we have to generalize the equations used in the model and to analyse the influence of ionization and chemical quench in both spectra and counting efficiency. We present equations to study the influence of different photomultipliers response in systems with one, two or three photomultipliers. We study the effect of the electronic noise discriminator level in both spectra and counting efficiency. The described method permits one to study problems that up to now was not possible to approach, such as the high uncertainty in the standardization of pure beta-ray emitter with low energy when we apply the TDCR method, or the discrepancies in the standardization of some electron capture radionuclides, when the CIEMAT/NIST method is applied. (Author) 107 refs.

  3. Development of liquid scintillator containing a zirconium complex for neutrinoless double beta decay experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Yoshiyuki, E-mail: fukuda@staff.miyakyo-u.ac.jp [Department of Physics, Miyagi University of Education, Sendai, Miyagi 980-0845 (Japan); Moriyama, Shigetaka [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Hida, Gifu 506-1205 (Japan); Ogawa, Izumi [Faculty of Engineering, Fukui University, Fukui-shi, Fukui 910-8507 (Japan)

    2013-12-21

    An organic liquid scintillator containing a zirconium complex has been developed for a new neutrinoless double beta decay experiment. In order to produce a detector that has good energy resolution (4% at 2.5 MeV) and low background (0.1counts/(t·year)) and that can monitor tons of target isotope, we chose a zirconium β-diketone complex having high solubility (over 10 wt%) in anisole. However, the absorption peak of the diketone ligand overlaps with the luminescence of anisole. Therefore, the light yield of the liquid scintillator decreases in proportion to the concentration of the complex. To avoid this problem, we synthesized a β-keto ester complex introducing –OC{sub 3}H{sub 7} or –OC{sub 2}H{sub 5} substituent groups in the β-diketone ligand, which shifted the absorption peak to around 245 nm, which is shorter than the emission peak of anisole (275 nm). However, the shift of the absorption peak depends on the polarity of the scintillation solvent. Therefore we must choose a low polarity solvent for the liquid scintillator. We also synthesized a Zr–ODZ complex, which has a high quantum yield (30%) and good emission wavelength (425 nm) with a solubility 5 wt% in benzonitrile. However, the absorption peak of the Zr–ODZ complex was around 240 nm. Therefore, it is better to use the scintillation solvent which has shorter luminescence wavelength than that of the aromatic solvent.

  4. Measurement of Trace $^{129}I$ Concentrations in CsI Powder and Organic Liquid Scintillator with Accelerator Mass Spectrometry

    CERN Document Server

    Dong, K J

    2007-01-01

    Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Procedures were devised to measure trace concentrations of I-129 in the inorganic salt CsI as well as in organic liquid scintillator with Accelerator Mass Spectrometry (AMS) which leads to improvement in sensitivities by several orders of magnitude over other methods. No evidence of their existence in these materials were observed. Limits of < 6 X 10^{-13} g/g and < 2.6 X 10^{-17} g/g on the contaminations of I-129 in CsI and liquid scintillator, respectively, were derived.These are the first results in a research program whose goals are to develop techniques to measure trace radioactivity in detector materials by AMS.

  5. High-resolution tracking using large capillary bundles filled with liquid scintillator

    CERN Document Server

    Annis, P; Benussi, L; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Van Dantzig, R; Dupraz, J P; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Feyt, J; Frekers, D; Frenkel, A; Galeazzi, F; Garufi, F; Goldberg, J; Golovkin, S V; Gorin, A M; Grégoire, G; Harrison, K; Höpfner, K; Holtz, K; Konijn, J; Kozarenko, E N; Kreslo, I E; Kushnirenko, A E; Liberti, B; Martellotti, G; Medvedkov, A M; Michel, L; Migliozzi, P; Mommaert, C; Mondardini, M R; Panman, J; Penso, G; Petukhov, Yu P; Rondeshagen, D; Siegmund, W P; Tyukov, V E; Van Beek, G; Vasilchenko, V G; Vilain, P; Visschers, J L; Wilquet, G; Winter, Klaus; Wolff, T; Wörtche, H J; Wong, H; Zimyn, K V

    2000-01-01

    We have developed large high-resolution tracking detectors based on glass capillaries filled with organic liquid scintillator of high refractive index. These liquid-core scintillating optical fibres act simultaneously as detectors of charged particles and as image guides. Track images projected onto the readout end of a capillary bundle are visualized by an optoelectronic chain consisting of a set of image-intensifier tubes followed by a photosensitive CCD or by an EBCCD camera. Two prototype detectors, each composed of \\hbox{$\\approx 10^6$} capillaries with \\hbox{20$-$25 $\\mu$m} diameter and \\hbox{0.9$-$1.8 m} length, have been tested, and a spatial resolution of the order of \\hbox{20$-$40 $\\mu$m} has been attained. A high scintillation efficiency and a large light-attenuation length, in excess of 3 m, was achieved through special purification of the liquid scintillator. Along the tracks of minimum-ionizing particles, the hit densities obtained were $\\sim$ 8 hits/mm at the readout window, and \\hbox{$\\sim$ 3 ...

  6. Aging research of the LAB-based liquid scintillator in stainless steel container

    OpenAIRE

    Chen, Hai-tao; Yu, Bo-Xiang; Shan, Qing; Ding, Ya-yun; Du, Bing; Liu, Shu-tong; Zhang, Xuan; Zhou, Li; Jia, Wen-bao; Fang, Jian; Ye, Xing-Chen; HU, Wei; Niu, Shun-Li; Yan, Jia-qing; Zhao, Hang

    2014-01-01

    Stainless steel is the material used for the storage vessels and piping systems of LAB-based liquid scintillator in JUNO experiment. Aging is recognized as one of the main degradation mechanisms affecting the properties of liquid scintillator. LAB-based liquid scintillator aging experiments were carried out in different material of containers (type 316 and 304 stainless steel and glass) at two different temperature (40 and 25 degrees Celsius). For the continuous liquid scintillator properties...

  7. Neutron detection in a high gamma-ray background with EJ-301 and EJ-309 liquid scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Stevanato, L., E-mail: luca.stevanato@pd.infn.it [Dipartimento di Fisica ed Astronomia dell' Universita di Padova, Fisica ' Galileo Galilei' , Via Marzolo 8, I-35131 Padova (Italy); Cester, D. [Dipartimento di Fisica ed Astronomia dell' Universita di Padova, Fisica ' Galileo Galilei' , Via Marzolo 8, I-35131 Padova (Italy); Nebbia, G. [INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Viesti, G. [Dipartimento di Fisica ed Astronomia dell' Universita di Padova, Fisica ' Galileo Galilei' , Via Marzolo 8, I-35131 Padova (Italy)

    2012-10-21

    Using a fast digitizer, the neutron-gamma discrimination capability of the new liquid scintillator EJ-309 is compared with that obtained using standard EJ-301. Moreover the capability of both the scintillation detectors to identify a weak neutron source in a high gamma-ray background is demonstrated. The probability of neutron detection is PD=95% at 95% confidence level for a gamma-ray background corresponding to a dose rate of 100 {mu}Sv/h.

  8. A feasibility study of boron-loaded liquid scintillator for the detection of electron anti-neutrinos

    CERN Document Server

    Wang, S C; Leung, R W S; Wang, S L; Chang, C Y; Chen Chi Ping; Cheng, K C; Ho, T I; Lai, W P; Liu, H M; Mao, Z P; Shih, I C; Wong, H T; Yu, Z Q

    1999-01-01

    Boron-loaded liquid scintillator offers some potential advantages as a detector for electron anti-neutrinos. A research program was carried out with the objective of developing such scintillators. The crucial feature is the pulse shape discrimination properties following the neutron capture by sup 1 sup 0 B. Results of the R and D efforts are presented. The feasibility and the technical difficulties of carrying out a full-scale neutrino experiment based on this approach are discussed. (author)

  9. Quenching measurements and modeling of a boron-loaded organic liquid scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Westerdale, S.; Xu, J.; Shields, E.; Froborg, F.; Calaprice, F.; Alexander, T.; Aprahamian, A.; Back, H. O.; Casarella, C.; Fang, X.; Gupta, Y. K.; Lamere, E.; Liu, Q.; Lyons, S.; Smith, M.; Tan, W.

    2017-08-01

    Organic liquid scintillators are used in a wide variety of applications in experimental nuclear and particle physics. Boron-loaded scintillators are particularly useful for detecting neutron captures, due to the high thermal neutron capture cross section of 10B. These scintillators are commonly used in neutron detectors, including the DarkSide-50 neutron veto, where the neutron may produce a signal when it scatters o protons in the scintillator or when it captures on 10B. Reconstructing the energy of these recoils is complicated by scintillation quenching. Understanding how nuclear recoils are quenched in these scintillators is an important and dicult problem. In this article, we present a set of measurements of neutron-induced proton recoils in a boron-loaded organic liquid scintillator at recoil energies ranging from 57-467 keV, and we compare these measurements to predictions from different quenching models. We and that a modified Birks' model whose denominator is quadratic in dE=dx best describes the measurements, with χ2/NDF = 1:6. This result will help model nuclear recoil scintillation in similar detectors and can be used to improve their neutron tagging efficiency.

  10. Quenching Measurements and Modeling of a Boron-Loaded Organic Liquid Scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Westerdale, Shawn [Princeton U.; Xu, Jingke [Princeton U.; Shields, Emily [Princeton U.; Froborg, Francis [Princeton U.; Calaprice, Frank [Princeton U.; Alexander, Thomas [Fermilab; Aprahamian, Ani [Notre Dame U.; Back, Henning O. [Princeton U.; Casarella, Clark [Notre Dame U.; Fang, Xiao [Notre Dame U.; Gupta, Yogesh K. [Notre Dame U.; Lamere, Edward [Notre Dame U.; Liu, Qian [Notre Dame U.; Lyons, Stephanie [Notre Dame U.; Smith, Mallory [Notre Dame U.; Tan, Wanpeng [Notre Dame U.

    2017-03-18

    Organic liquid scintillators are used in a wide variety of applications in experimental nuclear and particle physics. Boron-loaded scintillators are particularly useful for detecting neutron captures, due to the high thermal neutron capture cross section of $^{10}$B. These scintillators are commonly used in neutron detectors, including the DarkSide-50 neutron veto, where the neutron may produce a signal when it scatters off protons in the scintillator or when it captures on $^{10}$B. Reconstructing the energy of these recoils is complicated by scintillation quenching. Understanding how nuclear recoils are quenched in these scintillators is an important and difficult problem. In this article, we present a set of measurements of neutron-induced proton recoils in a boron-loaded organic liquid scintillator at recoil energies ranging from 57--467 keV, and we compare these measurements to predictions from different quenching models. We find that a modified Birks' model whose denominator is quadratic in $dE/dx$ best describes the measurements, with $\\chi^2$/NDF$=1.6$. This result will help model nuclear recoil scintillation in similar detectors and can be used to improve their neutron tagging efficiency.

  11. High Resolution Tracking Devices Based on Capillaries Filled with Liquid Scintillator

    CERN Multimedia

    Bonekamper, D; Vassiltchenko, V; Wolff, T

    2002-01-01

    %RD46 %title\\\\ \\\\The aim of the project is to develop high resolution tracking devices based on thin glass capillary arrays filled with liquid scintillator. This technique provides high hit densities and a position resolution better than 20 $\\mu$m. Further, their radiation hardness makes them superior to other types of tracking devices with comparable performance. Therefore, the technique is attractive for inner tracking in collider experiments, microvertex devices, or active targets for short-lived particle detection. High integration levels in the read-out based on the use of multi-pixel photon detectors and the possibility of optical multiplexing allow to reduce considerably the number of output channels, and, thus, the cost for the detector.\\\\ \\\\New optoelectronic devices have been developed and tested: the megapixel Electron Bombarded CCD (EBCCD), a high resolution image-detector having an outstanding capability of single photo-electron detection; the Vacuum Image Pipeline (VIP), a high-speed gateable pi...

  12. Comparing the response of PSD-capable plastic scintillator to standard liquid scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Woolf, Richard S., E-mail: richard.woolf@nrl.navy.mil [High Energy Space Environment Branch, Space Science Division, U. S. Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 (United States); Hutcheson, Anthony L., E-mail: anthony.hutcheson@nrl.navy.mil [High Energy Space Environment Branch, Space Science Division, U. S. Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 (United States); Gwon, Chul, E-mail: chul.gwon@nrl.navy.mil [High Energy Space Environment Branch, Space Science Division, U. S. Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 (United States); Phlips, Bernard F., E-mail: bernard.phlips@nrl.navy.mil [High Energy Space Environment Branch, Space Science Division, U. S. Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 (United States); Wulf, Eric A., E-mail: eric.wulf@nrl.navy.mil [High Energy Space Environment Branch, Space Science Division, U. S. Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 (United States)

    2015-06-01

    This work discusses a test campaign to characterize the response of the recently developed plastic scintillator with pulse shape discrimination (PSD) capabilities (EJ-299-33). PSD is a property exhibited by certain types of scintillating material in which incident stimuli (fast neutrons or γ rays) can be separated by exploiting differences in the scintillation light pulse tail. Detector geometries used were: a 10 cm×10 cm×10 cm cube and a 10-cm diameter×10-cm long cylinder. EJ-301 and EJ-309 liquid scintillators with well-known responses were also tested. The work was conducted at the University of Massachusetts Lowell Van De Graaff accelerator. The facility accelerated protons on a thin Li target to yield quasi-monoenergetic neutrons from the {sup 7}Li(p,n){sup 7}Be reaction (Q-value: –1.644 MeV). Collimated fast neutrons were obtained by placing detectors behind a neutron spectrometer. Rotating the spectrometer, and thus changing the neutron energy, allowed us to achieve 0.5–3.2 MeV neutrons in 200–300 keV steps. Data were acquired through a flash analog-to-digital converter (ADC) capable of performing digital PSD measurements. By using the PSD technique to separate the neutron events from unwanted γ background, we constructed a pulse height spectrum at each energy. Obtaining a relationship of the relative light output versus energy allowed us to construct the response function for the EJ-299-33 and liquid scintillator. The EJ-299-33 response in terms of electron equivalent energy (E{sub e.e.}) vs. proton equivalent energy (E{sub p.e.}), how it compared with the standard xylene-based EJ-301 (or, NE-213/BC-501 A equivalent) and EJ-309 liquid scintillator response, and how the EJ-301 and EJ-309 compared, are presented. We find that the EJ-299-33 demonstrated a lower light output by up to 40% for <1.0 MeV neutrons; and ranging between a 5–35% reduction for 2.5–3.0 MeV neutrons compared to the EJ-301/309, depending on the scintillator and geometry

  13. Characterization of positronium properties in doped liquid scintillators

    CERN Document Server

    Consolati, G; Hans, S; Jollet, C; Meregaglia, A; Perasso, S; Tonazzo, A; Yeh, M

    2013-01-01

    Ortho-positronium (o-Ps) formation and decay can replace the annihilation process, when positron interacts in liquid scintillator media. The delay induced by the positronium decay represents either a potential signature for anti-neutrino detection, via inverse beta decay, or to identify and suppress positron background, as recently demonstrated by the Borexino experiment. The formation probability and decay time of o-Ps depend strongly on the surrounding material. In this paper, we characterize the o-Ps properties in liquid scintillators as function of concentrations of gadolinium, lithium, neodymium, and tellurium, dopers used by present and future neutrino experiments. In particular, gadolinium and lithium are high neutron cross section isotopes, widely used in reactor anti-neutrino experiments, while neodymium and tellurium are double beta decay emitters, employed to investigates the Majorana neutrino nature. Future neutrino experiments may profit from the performed measurements to tune the preparation of ...

  14. 13C(alpha,n)16O background in a liquid scintillator based neutrino experiment

    CERN Document Server

    Zhao, Jie; Liu, Jianglai; Li, Xiaobo; Zhang, Feihong; Xia, Dongmei

    2013-01-01

    Alpha from natural radioactivity may interact with a nucleus and emit a neutron. The reaction introduces background to the liquid scintillator (LS) based neutrino experiments. In the LS detector, alpha comes from 238U, 232Th and 210Po decay chains. For Gadolinium-doped LS (Gd-LS) detector, alpha also comes from 227Ac. The nucleus 13C is a natural component of Carbon which is rich in the LS. The background rate and spectrum should be subtracted carefully from the neutrino candidates. This paper describes the calculation of neutron yield and spectrum with uncertainty estimated. The results are relevant for many existing neutrino experiments and future LS or Gd-LS based experiments.

  15. Rare-earth loaded liquid scintillator (for LENS experiment)

    CERN Document Server

    Barabanov, I R; Kornoukhov, V N; Yanovich, E A; Zatsepin, G T; Danilov, N A; Korpusov, G V; Kostukova, G V; Krylov, Y S; Yakshin, V V

    1999-01-01

    Rare-earth (Yb/Gd) complexes with neutral organophosphorus ligands are briefly discussed for their application in liquid scintillation technique. To evaluate the principal feasibility of rare-earth loaded scintillator, the ytterbium chloride complexes with tri-isoamylphosphine oxides were synthesized. Relative scintillation efficiency (RSE) for two Yb concentrations (78 and 88 g/L) was measured by means of the internal conversion exitation from Cs-137. The results obtained were 50 and 40% respectively.

  16. Liquid Scintillation Counting - Packard Triple-Label Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Torretto, P. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-23

    The Radiological Measurements Laboratory (RML) maintains and operates nine Packard Liquid Scintillation Counters (LSCs). These counters were obtained through various sources and were generally purchased as 2500, 2700 or 3100 series counters. In 2004/2005 the software and firmware on the counters were upgraded. The counters are now designated as 3100 series counters running the Quantasmart software package. Thus, a single procedure can be used to calibrate and operate the Packard LSCs.

  17. Positronium signature in organic liquid scintillators for neutrino experiments

    CERN Document Server

    Franco, D; Trezzi, D

    2010-01-01

    Electron anti-neutrinos are commonly detected in liquid scintillator experiments via inverse beta decay, by looking at the coincidence between the reaction products, neutron and positron. Prior to positron annihilation, an electron-positron pair may form an orthopositronium (o-Ps) state, with a mean life of a few ns. Even if the o-Ps decay is speeded up by spin flip or pick off effects, it may introduce distortions in the photon emission time distribution, crucial for position reconstruction and pulse shape discrimination algorithms in anti-neutrino experiments. Reversing the problem, the o-Ps induced time distortion represents a new signature for tagging anti-neutrinos in liquid scintillator. In this paper, we report the results of measurements of the o-Ps formation probability and lifetime, for the most used solvents for organic liquid scintillators in neutrino physics (pseudocumene, linear alkyl benzene, phenylxylylethane, and dodecane). We characterize also a mixture of pseudocumene +1.5 g/l of 2,5-diphen...

  18. A Performance Comparison of Nine Selected Liquid Scintillation Cocktails

    Energy Technology Data Exchange (ETDEWEB)

    Verrezen, F.; Loots, H.; Hurtgen, Ch.

    2008-06-15

    In the selection of a suitable liquid scintillation (LSC) cocktail, the primary aspects taken into consideration are overall cocktail performance and specific laboratory needs. Overall performance of 9 selected, commercially available LSC cocktails was assessed by studying parameters of importance for the requirements of the Laboratory for Low Level Radioactivity Measurements of SCK-CEN: sample load capacity, sample compatibility, influence of sample load on counting efficiency, background count rate, figure of merit, quench resistance, sample stability and alpha/beta separation characteristics. The cocktails tested were EcoscintA, Insta Gel Plus, OptiPhase Hisafe3, OptiPhase Trisafe, Ready Gel, SafeScint 1:1, Ultima Gold, Ultima Gold LLT, and Ultima Gold XR. For the data acquisition a Packard TriCarb Model 1900CA and a Quantulus 1220 liquid scintillation counter is used. All samples were prepared in either 20 mL low potassium, borosilicate glass vials or 20 mL high density, polyethylene vials. The aim of this study was to determine a single cocktail that best suits all measurement requirements of the liquid scintillation laboratory at SCK-CEN for the determination of low levels of radioactivity in biological and environmental samples. As a conclusion, Optiphase HiSafe 3 was confirmed to be the optimal cocktail for the laboratory.

  19. Comparing the response of PSD-capable plastic scintillator to standard liquid scintillator

    Science.gov (United States)

    Woolf, Richard S.; Hutcheson, Anthony L.; Gwon, Chul; Phlips, Bernard F.; Wulf, Eric A.

    2015-06-01

    This work discusses a test campaign to characterize the response of the recently developed plastic scintillator with pulse shape discrimination (PSD) capabilities (EJ-299-33). PSD is a property exhibited by certain types of scintillating material in which incident stimuli (fast neutrons or γ rays) can be separated by exploiting differences in the scintillation light pulse tail. Detector geometries used were: a 10 cm×10 cm×10 cm cube and a 10-cm diameter×10-cm long cylinder. EJ-301 and EJ-309 liquid scintillators with well-known responses were also tested. The work was conducted at the University of Massachusetts Lowell Van De Graaff accelerator. The facility accelerated protons on a thin Li target to yield quasi-monoenergetic neutrons from the 7Li(p,n)7Be reaction (Q-value: -1.644 MeV). Collimated fast neutrons were obtained by placing detectors behind a neutron spectrometer. Rotating the spectrometer, and thus changing the neutron energy, allowed us to achieve 0.5-3.2 MeV neutrons in 200-300 keV steps. Data were acquired through a flash analog-to-digital converter (ADC) capable of performing digital PSD measurements. By using the PSD technique to separate the neutron events from unwanted γ background, we constructed a pulse height spectrum at each energy. Obtaining a relationship of the relative light output versus energy allowed us to construct the response function for the EJ-299-33 and liquid scintillator. The EJ-299-33 response in terms of electron equivalent energy (Ee.e.) vs. proton equivalent energy (Ep.e.), how it compared with the standard xylene-based EJ-301 (or, NE-213/BC-501 A equivalent) and EJ-309 liquid scintillator response, and how the EJ-301 and EJ-309 compared, are presented. We find that the EJ-299-33 demonstrated a lower light output by up to 40% for <1.0 MeV neutrons; and ranging between a 5-35% reduction for 2.5-3.0 MeV neutrons compared to the EJ-301/309, depending on the scintillator and geometry. Monte Carlo modeling techniques were

  20. A Novel Particle Detector: Quantum Dot Doped Liquid Scintillator

    Science.gov (United States)

    Winslow, Lindley; Conrad, Janet; Jerry, Ruel

    2010-02-01

    Quantum dots are semiconducting nanocrystals. When excited by light shorter then their characteristic wavelength, they re-emit in a narrow band around this wavelength. The size of the quantum is proportional to the characteristic wavelength so they can be tuned for many applications. CdS quantum dots are made in wavelengths from 360nm to 460nm, a perfect range for the sensitivity of photo-multiplier tubes. The synthesis of quantum dots automatically leaves them in toluene, a good organic scintillator and Cd is a particularly interesting material as it has one of the highest thermal neutron cross sections and has several neutrinoless double beta decay and double electron capture isotopes. The performance of quantum dot loaded scintillator compared to standard scintillators is measured and some unique properties presented. )

  1. Discrimination in Liquid Scintillator and Its Usage to Suppress $^{8}$He/$^{9}$Li Backgrounds

    CERN Document Server

    Cheng, Ya-Ping; Zhang, Peng; Cao, Xing-Zhong

    2016-01-01

    Reactor neutrino experiments build large-scale detector systems to trap ghost-like neutrinos. In liquid scintillator, a neutral bound state of a positron and an electron named positronium could be formed. The spin triplet state was called ortho-positronium (o-Ps). In this script, an experiment was designed to measure the lifetime of o-Ps, which turned out to be 3.1 ns. A PSD parameter based on photon emission time distribution (PETD) was constructed to discriminate e$^+$/e$^-$. Finally the application of e$^+$/e$^-$ discrimination in JUNO experiment was shown. It helps suppression of $^{8}$He/$^{9}$Li backgrounds and improves the sensitivity by 0.6 in $\\chi^2$ analysis with assumption of $\\sigma=1$ ns PMT Transit Time Spread, which will bring smearing effect to PETD.

  2. Suppression of gamma-ray sensitivity of liquid scintillators for neutron detection

    Science.gov (United States)

    Swiderski, L.; Moszyński, M.; Wolski, D.; Iwanowska, J.; Szczęśniak, T.; Schotanus, P.; Hurlbut, C.

    2011-10-01

    Methods to reduce gamma-ray sensitivity of a liquid scintillator EJ309 have been studied. Zero-crossing pulse shape discrimination method was used to separate events generated by neutron and gamma radiation between 60- keVee and 4 MeVee. The measurements were carried out under irradiation from an intense 137Cs source, yielding dose rate of 10 mR/h at the detector. A Pu-Be source was used to establish neutron integration window. Pile-up rejection (PUR) circuit was used to reduce gamma-ray induced events under irradiation from an intense gamma-ray source. Further, application of lead, tin and copper shields was done in order to decrease intrinsic gamma-neutron detection efficiency.

  3. Suppression of gamma-ray sensitivity of liquid scintillators for neutron detection

    Energy Technology Data Exchange (ETDEWEB)

    Swiderski, L., E-mail: l.swiderski@ipj.gov.pl [Soltan Institute for Nuclear Studies, PL 05-400 Otwock-Swierk (Poland); Moszynski, M.; Wolski, D.; Iwanowska, J.; Szczesniak, T. [Soltan Institute for Nuclear Studies, PL 05-400 Otwock-Swierk (Poland); Schotanus, P. [Scionix Holland B.V., 3980 CC Bunnik (Netherlands); Hurlbut, C. [Eljen Technology, 2010 E. Broadway, Sweetwater, TX 79556 (United States)

    2011-10-01

    Methods to reduce gamma-ray sensitivity of a liquid scintillator EJ309 have been studied. Zero-crossing pulse shape discrimination method was used to separate events generated by neutron and gamma radiation between 60- keVee and 4 MeVee. The measurements were carried out under irradiation from an intense {sup 137}Cs source, yielding dose rate of 10 mR/h at the detector. A Pu-Be source was used to establish neutron integration window. Pile-up rejection (PUR) circuit was used to reduce gamma-ray induced events under irradiation from an intense gamma-ray source. Further, application of lead, tin and copper shields was done in order to decrease intrinsic gamma-neutron detection efficiency.

  4. Application of pulse decay discrimination liquid scintillation counting for indoor radon measurement

    Science.gov (United States)

    Bem, H.; Ostrowska, M.; Bem, E. M.

    1999-01-01

    The pulse decay discrimination (PDD) liquid scintillation technique has been applied to optimise radon counting by the Pico-Rad method. A dermination limit (with 10% relative error) of 4.8 Bqm-3 for indoor radon measurement has been achieved for optimal PDD setting with a radon elution cocktail containing 20% (v/v) of Ultima Gold AB in Instafluor. From a practical point of view this procedure allows a shortening of the counting time to 1 hour after 48 hours exposure to detectors. This method has been applied to indoor radon determinations in 626 places (municipal offices and private dwellings) in the Lódz region. These measureents resulted in an average concentration of 21.4 Bqm-3 and a median value of 15.1 Bqm-3. Analysis of the data indicates that most indoor radon comes from the underlying soil, which contains relatively little226Ra (10-20 Bqkg-1).

  5. Measurement of the neutron spectrum of a Pu-C source with a liquid scintillator

    Institute of Scientific and Technical Information of China (English)

    WANG Song-Lin; HUANG Han-Xiong; RUAN Xi-Chao; LI Xia; BAO Jie; NIE Yang-So; ZHONG Qi-Ping; ZHOU Zu-Ying; KONG Xiang-Zhong

    2009-01-01

    The neutron response function for a BC501A liquid scintillator (LS) has been measured using a series of monoenergetic neutrons produced by the p-T reaction. The proton energies were chosen such as to produce neutrons in the energy range of 1 to 20 MeV. The principles of the technique of unfolding a neutron energy spectrum by using the measured neutron response function and the measured Pulse Height (PH) spectrum is briefly described. The PH spectrum of neutrons from the Pu-C source, which will be used for the calibration of the reactor antineutrino detectors for the Daya Bay neutrino experiment, was measured and analyzed to get the neutron energy spectrum. Simultaneously the neutron energy spectrum of an Am-Be source was measured and compared with other measurements as a check of the result for the Pu-C source. Finally, an error analysis and a discussion of the results are given.

  6. Detecting energy dependent neutron capture distributions in a liquid scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Balmer, Matthew J.I., E-mail: m.balmer@lancaster.ac.uk [Department of Engineering, Lancaster University, LA1 4YR (United Kingdom); Gamage, Kelum A.A. [Department of Engineering, Lancaster University, LA1 4YR (United Kingdom); Taylor, Graeme C. [Neutron Metrology Group, National Physical Laboratory, Teddington, TW11 0LW (United Kingdom)

    2015-03-11

    A novel technique is being developed to estimate the effective dose of a neutron field based on the distribution of neutron captures in a scintillator. Using Monte Carlo techniques, a number of monoenergetic neutron source energies and locations were modelled and their neutron capture response was recorded. Using back propagation Artificial Neural Networks (ANN) the energy and incident direction of the neutron field was predicted from the distribution of neutron captures within a {sup 6}Li-loaded liquid scintillator. Using this proposed technique, the effective dose of {sup 252}Cf, {sup 241}AmBe and {sup 241}AmLi neutron fields was estimated to within 30% for four perpendicular angles in the horizontal plane. Initial theoretical investigations show that this technique holds some promise for real-time estimation of the effective dose of a neutron field.

  7. Aging research of the LAB-based liquid scintillator in stainless steel container

    CERN Document Server

    Chen, Hai-tao; Shan, Qing; Ding, Ya-yun; Du, Bing; Liu, Shu-tong; Zhang, Xuan; Zhou, Li; Jia, Wen-bao; Fang, Jian; Ye, Xing-chen; Hu, Wei; Niu, Shun-li; Yan, Jia-qing; Zhao, Hang; Zhao, Dao-jin

    2014-01-01

    Stainless steel is the material used for the storage vessels and piping systems of LAB-based liquid scintillator in JUNO experiment. Aging is recognized as one of the main degradation mechanisms affecting the properties of liquid scintillator. LAB-based liquid scintillator aging experiments were carried out in different material of containers (type 316 and 304 stainless steel and glass) at two different temperature (40 and 25 degrees Celsius). For the continuous liquid scintillator properties tests, the light yield and the absorption spectrum are nearly the same as that of the unaged one. The attenuation length of the aged samples is 6%~12% shorter than that of the unaged one. But the concentration of element Fe in the LAB-based liquid scintillator does not show a clear change. So the self aging has small effect on liquid scintillator, as well as the stainless steel impurity quenching. Type 316 and 304 stainless steel can be used as LAB-based liquid scintillator vessel, transportation pipeline material.

  8. Production of Gadolinium-loaded Liquid Scintillator for the Daya Bay Reactor Neutrino Experiment

    CERN Document Server

    Beriguete, Wanda; Ding, Yayun; Hans, Sunej; Heeger, Karsten M; Hu, Liangming; Huang, Aizhong; Luk, Kam-Biu; Nemchenok, Igor; Qi, Ming; Rosero, Richard; Sun, Hansheng; Wang, Ruiguang; Wang, Yifang; Wen, Liangjian; Yang, Yi; Yeh, Minfang; Zhang, Zhiyong; Zhou, Li

    2014-01-01

    We report on the production and characterization of liquid scintillators for the detection of electron antineutrinos by the Daya Bay Reactor Neutrino Experiment. One hundred eighty-five tons of gadolinium-loaded (0.1% by mass) liquid scintillator (Gd-LS) and two hundred tons of unloaded liquid scintillator (LS) were successfully produced from a linear-alkylbenzene (LAB) solvent in six months. The scintillator properties, the production and purification systems, and the quality assurance and control (QA/QC) procedures are described.

  9. Discrimination of neutrons and γ-rays in liquid scintillator based on Elman neural network

    Science.gov (United States)

    Zhang, Cai-Xun; Lin, Shin-Ted; Zhao, Jian-Ling; Yu, Xun-Zhen; Wang, Li; Zhu, Jing-Jun; Xing, Hao-Yang

    2016-08-01

    In this work, a new neutron and γ (n/γ) discrimination method based on an Elman Neural Network (ENN) is proposed to improve the discrimination performance of liquid scintillator (LS) detectors. Neutron and γ data were acquired from an EJ-335 LS detector, which was exposed in a 241Am-9Be radiation field. Neutron and γ events were discriminated using two methods of artificial neural network including the ENN and a typical Back Propagation Neural Network (BPNN) as a control. The results show that the two methods have different n/γ discrimination performances. Compared to the BPNN, the ENN provides an improved of Figure of Merit (FOM) in n/γ discrimination. The FOM increases from 0.907 ± 0.034 to 0.953 ± 0.037 by using the new method of the ENN. The proposed n/γ discrimination method based on ENN provides a new choice of pulse shape discrimination in neutron detection. Supported by National Natural Science Foundation of China (11275134,11475117)

  10. Biocomponent determination in vinegars with the help of 14C measured by liquid scintillation counting.

    Science.gov (United States)

    Tudyka, Konrad; Pawlyta, Jacek

    2014-02-15

    This article presents a method of carbon extraction from vinegar used in preparation of liquid scintillation counting cocktails for measurements of low (14)C radioactivity. The presented method is relatively fast and can be used to produce liquid scintillation cocktails e.g., via benzene synthesis. In this work we present specific radiocarbon radioactivity determinations and based on them estimation of bio product content for five commercially available vinegars. All investigated vinegars are likely produced from plants in fermentation process.

  11. Optimization of screening for radioactivity in urine by liquid scintillation.

    Energy Technology Data Exchange (ETDEWEB)

    Shanks, Sonoya Toyoko; Reese, Robert P.; Preston, Rose T. (Technadyne Engineering Consultants, Inc., Albuquerque, NM)

    2007-08-01

    Numerous events have or could have resulted in the inadvertent uptake of radionuclides by fairly large populations. Should a population receive an uptake, valuable information could be obtained by using liquid scintillation counting (LSC) techniques to quickly screen urine from a sample of the affected population. This study investigates such LSC parameters as discrimination, quench, volume, and count time to yield guidelines for analyzing urine in an emergency situation. Through analyzing variations of the volume and their relationships to the minimum detectable activity (MDA), the optimum ratio of sample size to scintillating chemical cocktail was found to be 1:3. Using this optimum volume size, the alpha MDA varied from 2100 pCi/L for a 30-second count time to 35 pCi/L for a 1000-minute count time. The typical count time used by the Sandia National Laboratories Radiation Protection Sample Diagnostics program is 30 minutes, which yields an alpha MDA of 200 pCi/L. Because MDA is inversely proportional to the square root of the count time, count time can be reduced in an emergency situation to achieve the desired MDA or response time. Note that approximately 25% of the response time is used to prepare the samples and complete the associated paperwork. It was also found that if the nuclide of interest is an unknown, pregenerated discriminator settings and efficiency calibrations can be used to produce an activity value within a factor of two, which is acceptable for a screening method.

  12. A high-resolution tracking hodoscope based on capillary layers filled with liquid scintillator

    CERN Document Server

    Bay, A; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Ekimov, A V; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Frekers, D; Frenkel, A; Golovkin, S V; Govorun, V N; Harrison, K; Koppenburg, P; Kozarenko, E N; Kreslo, I E; Liberti, B; Martellotti, G; Medvedkov, A M; Mondardini, M R; Penso, G; Siegmund, W P; Vasilchenko, V G; Vilain, P; Wilquet, G; Winter, Klaus; Wörtche, H J

    2001-01-01

    Results are given on tests of a high-resolution tracking hodoscope based on layers of \\hbox{26-$\\mu$m-bore} glass capillaries filled with organic liquid scintillator (1-methylnaphthalene doped with R39). The detector prototype consisted of three 2-mm-thick parallel layers, with surface areas of $2.1 \\times 21$~cm$^2$. The layers had a centre-to-centre spacing of 6~mm, and were read by an optoelectronic chain comprising two electrostatically focused image intensifiers and an Electron-Bombarded Charge-Coupled Device (EBCCD). Tracks of cosmic-ray particles were recorded and analysed. The observed hit density was 6.6~hits/mm for particles crossing the layers perpendicularly, at a distance of 1~cm from the capillaries' readout end, and 4.2~hits/mm for particles at a distance of 20~cm. A track segment reconstructed in a single layer had an rms residual of $\\sim$~20~$\\mu$m, and allowed determination of the track position in a neighbouring layer with a precision of $\\sim$~170~$\\mu$m. This latter value corresponded to...

  13. Laboratory Studies on the Removal of Radon-Born Lead from KamLAND's Organic Liquid Scintillator

    CERN Document Server

    Keefer, G; Piepke, A; Ebihara, T; Ikeda, H; Kishimoto, Y; Kibe, Y; Koseki, Y; Ogawa, M; Shirai, J; Takeuchi, S; Mauger, C; Zhang, C; Schweitzer, G; Berger, B E; Dazeley, S; Decowski, M P; Detwiler, J A; Djurcic, Z; Dwyer, D A; Efremenko, Y; Enomoto, S; Freedman, S J; Fujikawa, B K; Furuno, K; Gando, A; Gando, Y; Gratta, G; Hatakeyama, S; Heeger, K M; Hsu, L; Ichimura, K; Inoue, K; Iwamoto, T; Kamyshkov, Y; Karwowski, H J; Koga, M; Kozlov, A; Lane, C E; Learned, J G; Maricic, J; Marko, D M; Matsuno, S; McKee, D; McKeown, R D; Miletic, T; Mitsui, T; Motoki, M; Nakajima, K; Nakamura, K; O'Donnell, T; Ogawa, H; Piquemal, F; Ricol, J -S; Shimizu, I; Suekane, F; Suzuki, A; Svoboda, R; Tajima, O; Takemoto, Y; Tamae, K; Tolich, K; Tornow, W; Watanabe, Hideki; Watanabe, Hiroko; Winslow, L A; Yoshida, S

    2013-01-01

    The removal of radioactivity from liquid scintillator has been studied in preparation of a low background phase of KamLAND. This paper describes the methods and techniques developed to measure and efficiently extract radon decay products from liquid scintillator. We report the radio-isotope reduction factors obtained when applying various extraction methods. During this study, distillation was identified as the most efficient method for removing radon daughters from liquid scintillator.

  14. e+/e- discrimination in liquid scintillator and its usage to suppress 8He/9Li backgrounds

    Science.gov (United States)

    Cheng, Ya-Ping; Wen, Liang-Jian; Zhang, Peng; Cao, Xing-Zhong

    2017-01-01

    Reactor neutrino experiments build large-scale detector systems to detect neutrinos. In liquid scintillator, a neutral bound state of a positron and an electron, named positronium, can be formed. The spin triplet state is called ortho-positronium (o-Ps). In this article, an experiment is designed to measure the lifetime of o-Ps, giving a result of 3.1 ns. A PSD parameter based on photon emission time distribution (PETD) was constructed to discriminate e+/e-. Finally, the application of e+/e- discrimination in the JUNO experiment is shown. It helps suppress 8He/9Li backgrounds and improves the sensitivity by 0.6 in χ 2 analysis with an assumption of σ = 1 ns PMT Transit Time Spread, which will bring a smearing effect to the PETD. Supported by National Natural Science Foundation of China (11575226, 11475197, 11205183)

  15. Measurement of (90)Sr in environmental samples by cation-exchange and liquid scintillation counting.

    Science.gov (United States)

    Amano, H; Yanase, N

    1990-06-01

    A new method for the measurement of (90)Sr in environmental samples by cation-exchange and liquid scintillation counting is described. Strontium carbonate is purified by precipitation and ion-exchange, weighed for the determination of chemical yield, dissolved in hydrochloric acid and mixed with the liquid scintillator, Aquasol-2. Two channels of a low-background liquid scintillation counter are used to determine (90)Sr, (90)Y and (89)Sr, free from the effects of environmental tritium. The values of (90)Sr obtained by this method are in good agreement with those from ordinary (90)Y milking and the gas proportional counting method. The concentration of (90)Sr in the air at Tokai-mura in Japan has been measured by the new method.

  16. Calibration of an EJ309 liquid scintillator using an AmBe neutron source

    Science.gov (United States)

    Bai, Huaiyong; Wang, Zhimin; Zhang, Luyu; Lu, Yi; Jiang, Haoyu; Chen, Jinxiang; Zhang, Guohui

    2017-08-01

    As the light output function of the EJ309 liquid scintillator is nonlinear with respect to the energy of the recoil proton and it is difficult to be predicted, it need to be measured. In the present work, an EJ309 liquid scintillator, 5.1 cm in diameter and 5.1 cm in length, is calibrated with an AmBe neutron source using the time-of-flight method. A Monte Carlo simulation is performed to improve the accuracy of the measured light output function. The obtained light output function is presented and it is compared with existing measurements. The energy resolution of the EJ309 Liquid scintillator is also illustrated.

  17. Timing properties and pulse shape discrimination of LAB-based liquid scintillator

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Bo; XIAO Hua-Lin; CAO Jun; LI Jin; RUAN Xi-Chao; HENG Yue-Kun

    2011-01-01

    Linear Alkyl Benzene (LAB) is a promising liquid scintillator solvent in neutrino experiments because it has many appealing properties.The timing properties of LAB-based liquid scintillator have been studied through ultraviolet and ionization excitation in this study.The decay time of LAB,PPO and bis-MSB is found to be 48.6 ns,1.55 ns and 1.5 ns,respectively.A model can describe the absorption and re-emission process between PPO and bis-MSB perfectly.The energy transfer time between LAB and PPO with different concentrations can be obtained via another model.We also show that the LAB-based liquid scintillator has good (n,γ) and (α,γ) discrimination power.

  18. Development of a low background liquid scintillation counter for a shallow underground laboratory

    CERN Document Server

    Erchinger, J L; Bernacki, B E; Douglas, M; Fuller, E S; Keillor, M E; Morley, S M; Mullen, C A; Orrell, J L; Panisko, M E; Warren, G A; Williams, R O; Wright, M E

    2015-01-01

    Pacific Northwest National Laboratory has recently opened a shallow underground laboratory intended for measurement of low-concentration levels of radioactive isotopes in samples collected from the environment. The development of a low-background liquid scintillation counter is currently underway to further augment the measurement capabilities within this underground laboratory. Liquid scintillation counting is especially useful for measuring charged particle (e.g., $\\beta$, $\\alpha$) emitting isotopes with no (or very weak) gamma-ray yields. The combination of high-efficiency detection of charged particle emission in a liquid scintillation cocktail coupled with the low-background environment of an appropriately-designed shield located in a clean underground laboratory provides the opportunity for increased-sensitivity measurements of a range of isotopes. To take advantage of the 35 meters-water-equivalent overburden of the underground laboratory, a series of simulations have evaluated the scintillation count...

  19. Pulse-shape discrimination of scintillation from alpha and beta particles with liquid scintillator and Geiger-mode multipixel avalanche diodes

    CERN Document Server

    Kreslo, I; Delaquis, S; Ereditato, A; Janos, S; Messina, M; Moser, U; Rossi, B; Zeller, M

    2011-01-01

    A successfull application of Geiger-mode multipixel avalanche diodes (GMAPDs) for pulse-shape discrimination in alpha-beta spectrometry using organic liquid scintillator is described in this paper. Efficient discrimination of alpha and beta components in the emission of radioactive isotopes is achieved for alpha energies above 0.3 MeV. The ultra-compact design of the scintillating detector helps to efficiently suppress cosmic-ray and ambient radiation background. This approach allows construction of hand-held robust devices for monitoring of radioactive contamination in various environmental conditions.

  20. Influence of dissolved gas and temperature on the light yield of new liquid scintillators

    CERN Document Server

    Buontempo, S; Golovkin, S V; Martellotti, G; Medvedkov, A M; Penso, G; Soloviev, A S; Vasilchenko, V G

    1999-01-01

    Sixteen new liquid scintillators, emitting green light, were studied. They are based on four solvents combined with four dopants. The influence of different gas atmospheres was studied. In particular it was shown that by keeping these liquid scintillators in vacuum or in a neutral gas, the light yield increases up to 32~\\% at 20 $^{\\circ}$C and for the best solvent-dopant combinations. The dependance of the light yield on temperature was also studied for these scintillators. In the 20--60 $^{\\circ}$C interval, some exhibit a light yield variation of $\\sim$ 3 \\% which is smaller than that of the NE 102A plastic scintillator.

  1. Liquid scintillators with near infrared emission based on organoboron conjugated polymers.

    Science.gov (United States)

    Tanaka, Kazuo; Yanagida, Takayuki; Yamane, Honami; Hirose, Amane; Yoshii, Ryousuke; Chujo, Yoshiki

    2015-11-15

    The organic liquid scintillators based on the emissive polymers are reported. A series of conjugated polymers containing organoboron complexes which show the luminescence in the near infrared (NIR) region were synthesized. The polymers showed good solubility in common organic solvents. From the comparison of the luminescent properties of the synthesized polymers between optical and radiation excitation, similar emission bands were detected. In addition, less significant degradation was observed. These data propose that the organoboron conjugated polymers are attractive platforms to work as an organic liquid scintillator with the emission in the NIR region.

  2. Landau Energy Loss in Liquid Scintillator and the Search for Wifs with the LVD Experiment.

    Science.gov (United States)

    Tang, Jie

    The LVD experiment at Gran Sasso, Italy, is described, and data since the completion of the first tower (one fifth of the whole LVD) are analyzed. The dE/dx distribution of reconstructed high-energy muons in the scintillator counters is obtained. This distribution is compared with predictions by a GEANT3 Monte Carlo simulation of cosmic muons going through the LVD detector. Its shape is similar to the Landau approximation. In the data from a total running time of 245 days, 159286 clearly separable charged tracks going through the detector were reconstructed. No WIF (Weakly-Interacting Fractionally-charged particle) is observed. Since the early 1930's to the 1980's, theories on the dE/dx distribution of charged particles in matter have evolved from the fundamental work done by Bethe, Bloch, Landau, Symon, Vavilov and others with the inclusion of more precise corrections of the density effect and the shell effect. At the LVD experiment, through a procedure of gain-factor calibration at every period of 20 days, to compensate for instability and nonuniformity of the scintillator counters and their readout, the muon dE/dx distribution is measured; it conforms to the Landau approximation. The precision of the dE/dx measurement is 7.6% (one sigma).. WIF particles are speculated by modern theories. Because dE/dx is proportional to the square of the charge carried by the incident particle, any WIF going through the LVD liquid scintillator will reveal itself by its dE/dx being on the low side of the carefully calibrated muon dE/dx distribution. Calculation has shown that when the charge of a WIF is as low as {2over 3} e, it still generates enough ionization in the LVD limited streamer tubes and thus its track is as visible as a muon track in the detector. Such events are not found. Assuming a uniform flux distribution of WIF particles coming from the atmosphere, the upper limit of their flux at the LVD site is 4.4 times rm 10^{-14} cm^{-2}sterad ^{-1}sec^{-1}. (Copies

  3. Development of a low background liquid scintillation counter for a shallow underground laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Erchinger, Jennifer L.; Aalseth, Craig E.; Bernacki, Bruce E.; Douglas, Matthew; Fuller, Erin S.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Orrell, John L.; Panisko, Mark E.; Warren, Glen A.; Williams, Russell O.; Wright, Michael E.

    2015-08-20

    Pacific Northwest National Laboratory has recently opened a shallow underground laboratory intended for measurement of lowconcentration levels of radioactive isotopes in samples collected from the environment. The development of a low-background liquid scintillation counter is currently underway to further augment the measurement capabilities within this underground laboratory. Liquid scintillation counting is especially useful for measuring charged particle (e.g., B, a) emitting isotopes with no (orvery weak) gamma-ray yields. The combination of high-efficiency detection of charged particle emission in a liquid scintillation cocktail coupled with the low-background environment of an appropriately-designed shield located in a clean underground laboratory provides the opportunity for increased-sensitivity measurements of a range of isotopes. To take advantage of the 35-meter water-equivalent overburden of the underground laboratory, a series of simulations have evaluated the instrumental shield design requirements to assess the possible background rate achievable. This report presents the design and background evaluation for a shallow underground, low background liquid scintillation counter design for sample measurements.

  4. Isotope Fractionation in Methane Reactions Studied by Gas Chromatography and Liquid Scintillation

    DEFF Research Database (Denmark)

    Andersen, Bertel Lohmann; Bidoglio, G.; Leip, A.

    1997-01-01

    Determination of C-14-marked methane by gas chromatography and liquid scintillation counting is shown to be useful in studies of isotope effects. Data on the specific activity is used to separate the contributions of (CH4)-C-14, and (CH4)-C-12 to the gas-chromatographic peak area. As an application...

  5. Improved Scintillator Materials For Compact Electron Antineutrino Detectors

    NARCIS (Netherlands)

    Dijkstra, Peter; Wortche, Heinrich J.; Browne, Wesley R.

    2012-01-01

    Recent developments provide new components holding the potential to improve the performance of liquid scintillation electron antineutrino detectors used as nuclear reactors monitors. Current systems raise issues regarding size, quantum efficiency, stability, and spatial resolution of the vertex dete

  6. Neutron-Gamma Pulse Shape Discrimination with a NE-213 Liquid Scintillator by Using Digital Signal Processing Combined with Similarity Method

    Directory of Open Access Journals (Sweden)

    Mardiyanto

    2008-07-01

    Full Text Available Neutron-Gamma Pulse Shape Discrimination with a NE-213 Liquid Scintillator by Using Digital Signal Processing Combined with Similarity Method. Measurement of mixed neutron-gamma radiation is difficult because a neuclear detector is usually sensitive to both radiations. A new attempt of neutron-gamma pulse shape discrimination for a NE-213 liquid scintillator is presented by using digital signal processing combined with an off-line similarity method. The output pulse shapes are digitized with a high speed digital oscilloscope. The n-γ discrimination is done by calculating the index of each pulse shape, which is determined by the similarity method, and then fusing it with its corresponding pulse height. Preliminary results demonstrate good separation of neutron and gamma-ray signals from a NE-213 scintillator with a simple digital system. The results were better than those with a conventional rise time method. Figure of Merit is used to determine the quality of discrimination. The figure of merit of the discrimination using digital signal processing combined with of line similarity method are 1.9; 1.7; 1.1; 1.1; and 0.8 ; on the other hand by using conventional method the rise time are 0.9; 0.9; 0.9; 0.7; and 0.4 for the equivalent electron energy of 800 ; 278 ; 139 ; 69 ; and 30 keV

  7. Direct activity determination of Mn-54 and Zn-65 by a non-extrapolation liquid scintillation method

    CSIR Research Space (South Africa)

    Simpson, BRS

    2004-02-01

    Full Text Available The measurement of Mn-54 and Zn-65 by liquid scintillation coincidence counting results in low detection efficiencies. The activity obtained from the extrapolation of efficiency data can therefore become problematic if curvature is present...

  8. Fitting of alpha-efficiency versus quenching parameter by exponential functions in liquid scintillation counting

    Energy Technology Data Exchange (ETDEWEB)

    Sosa, M. [Departamento de Ingeniería Física, Campus León, Universidad de Guanajuato, 37150 León, Guanajuato (Mexico); Universidad de Sevilla, Departamento de Física Aplicada II, E.T.S. Arquitectura, Av. Reina Mercedes, 2, 41012 Sevilla (Spain); Manjón, G., E-mail: manjon@us.es [Universidad de Sevilla, Departamento de Física Aplicada II, E.T.S. Arquitectura, Av. Reina Mercedes, 2, 41012 Sevilla (Spain); Mantero, J.; García-Tenorio, R. [Universidad de Sevilla, Departamento de Física Aplicada II, E.T.S. Arquitectura, Av. Reina Mercedes, 2, 41012 Sevilla (Spain)

    2014-05-01

    The objective of this work is to propose an exponential fit for the low alpha-counting efficiency as a function of a sample quenching parameter using a Quantulus liquid scintillation counter. The sample quenching parameter in a Quantulus is the Spectral Quench Parameter of the External Standard (SQP(E)), which is defined as the number of channel under which lies the 99% of Compton spectrum generated by a gamma emitter ({sup 152}Eu). Although in the literature one usually finds a polynomial fitting of the alpha counting efficiency, it is shown here that an exponential function is a better description. - Highlights: • We have studied the quenching in alpha measurement by liquid scintillation counting. • We have reviewed typical fitting of alpha counting efficiency versus quenching parameter. • Exponential fitting of data is proposed as better fitting. • We consider exponential fitting has a physical basis.

  9. Efficiency calibration of a liquid scintillation counter for {sup 90}Y Cherenkov counting

    Energy Technology Data Exchange (ETDEWEB)

    Vaca, F. [Huelva Univ. (Spain). Dept. de Fisica Aplicada e Ingenieria Electrica; Manjon, G. [Departamento de Fisica Aplicada, E.T.S. de Arquitectura, Universidad de Sevilla, Av. Reina Mercedes, 2, E-41012 Sevilla (Spain); Garcia-Leon, M. [Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Fisica, Universidad de Sevilla, Av. Reina Mercedes, s/n. Apartado 1061, E-41080 Sevilla (Spain)

    1998-04-01

    In this paper a complete and self-consistent method for {sup 90}Sr determination in environmental samples is presented. It is based on the Cherenkov counting of {sup 90}Y with a conventional liquid scintillation counter. The effects of color quenching on the counting efficiency and background are carefully studied. A working curve is presented which allows to quantify the correction in the counting efficiency depending on the color quenching strength. (orig.). 6 refs.

  10. Measurement of actinides in environmental samples by Photo-Electron Rejecting Alpha Liquid Scintillation

    Energy Technology Data Exchange (ETDEWEB)

    Cadieux, J.R. [Westinghouse Savannah River Co., Aiken, SC (United States); Clark, S. [Savannah River Ecology Lab., Univ. of Georgia (United States); Fjeld, R.A.; Reboul, S.; Sowder, A. [Clemson Univ., SC (United States). Dept. of Environmental Systems Engineering

    1994-05-01

    This work describes the adaptation of extractive scintillation with a Photo-Electron Rejecting Alpha Liquid Scintillation (PERALS) (ORDELA, Inc.) spectrometer to the analysis of actinides in environmental samples from the Savannah River Site (SRS). Environmental quality assurance standards and actual water samples were treated by one of two methods; either a two step direct extraction, or for more complex samples, pretreatment by an extraction chromatographic separation prior to measurement of the alpha activity by PERALS.

  11. Development of an Ultra-Low Background Liquid Scintillation Counter for Trace Level Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Erchinger, Jennifer L.; Orrell, John L.; Aalseth, Craig E.; Bernacki, Bruce E.; Douglas, Matthew; Finn, Erin C.; Fuller, Erin S.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Panisko, Mark E.; Shaff, Sarah M.; Warren, Glen A.; Wright, Michael E.

    2015-09-01

    Low-level liquid scintillation counting (LSC) has been established as one of the radiation detection techniques useful in elucidating environmental processes and environmental monitoring around nuclear facilities. The Ultra-Low Background Liquid Scintillation Counter (ULB-LSC) under construction in the Shallow Underground Laboratory at Pacific Northwest National Laboratory aims to further reduce the MDAs and/or required sample processing. Through layers of passive shielding in conjunction with an active veto and 30 meters water equivalent overburden, the background reduction is expected to be 10 to 100 times below typical analytic low-background liquid scintillation systems. Simulations have shown an expected background of around 14 counts per day. A novel approach to the light collection will use a coated hollow light guide cut into the inner copper shielding. Demonstration LSC measurements will show low-energy detection, spectral deconvolution, and alpha/beta discrimination capabilities, from trials with standards of tritium, strontium-90, and actinium-227, respectively. An overview of the system design and expected demonstration measurements will emphasize the potential applications of the ULB-LSC in environmental monitoring for treaty verification, reach-back sample analysis, and facility inspections.

  12. Design of a Low Background Liquid Scintillation Counter for a Shallow Underground Laboratory

    Science.gov (United States)

    Orrell, John; Aalseth, Craig; Bernacki, Bruce; Douglas, Matt; Erchinger, Jennifer; Fuller, Erin; Keillor, Martin; Morley, Shannon; Mullen, Crystal; Panisko, Mark; Shaff, Sarah; Warren, Glen; Wright, Michael

    2014-09-01

    Pacific Northwest National Laboratory operates a 35-meter water-equivalent overburden, shallow underground laboratory for measuring low-concentration radioactive isotopes in environmental samples collected. A low-background liquid scintillation counter is under development. Liquid scintillation counting is useful for beta-emitting isotopes without (or low) gamma ray yields. The high-efficiency beta detection in a liquid scintillation cocktail coupled with the low-background environment of a shield located in a clean underground laboratory provides for increased-sensitivity measurements to a range of isotopes. Benchmarked simulations have evaluated the shield design requirements to assess the background rate achievable. Assay of shield construction materials provides the basis for the shield design development. The low background design is informed by efforts in experimental design of neutrinoless double beta decay experiments, direct detection dark matter experiments, and low energy neutrino detection experiments. In this vein a background budget for the instrument is presented with attention to low background methods directed toward applications of nuclear measurements.

  13. Monte Carlo simulation of a single detector unit for the neutron detector array NEDA

    Energy Technology Data Exchange (ETDEWEB)

    Jaworski, G. [Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warszawa (Poland); Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, PL 02-093 Warszawa (Poland); Palacz, M., E-mail: palacz@slcj.uw.edu.pl [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, PL 02-093 Warszawa (Poland); Nyberg, J. [Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Angelis, G. de [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); France, G. de [GANIL, Caen (France); Di Nitto, A. [INFN Sezione di Napoli, Napoli (Italy); Egea, J. [Department of Electronic Engineering, University of Valencia, Burjassot (Valencia) (Spain); IFIC-CSIC, University of Valencia, Valencia (Spain); Erduran, M.N. [Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University Istanbul (Turkey); Ertuerk, S. [Nigde Universitesi, Fen-Edebiyat Falkueltesi, Fizik Boeluemue, Nigde (Turkey); Farnea, E. [INFN Sezione di Padova, Padua (Italy); Gadea, A. [IFIC-CSIC, University of Valencia, Valencia (Spain); Gonzalez, V. [Department of Electronic Engineering, University of Valencia, Burjassot (Valencia) (Spain); Gottardo, A. [Padova University, Padua (Italy); Hueyuek, T. [IFIC-CSIC, University of Valencia, Valencia (Spain); Kownacki, J. [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, PL 02-093 Warszawa (Poland); Pipidis, A. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); Roeder, B. [LPC-Caen, ENSICAEN, IN2P3/CNRS et Universite de Caen, Caen (France); Soederstroem, P.-A. [Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Sanchis, E. [Department of Electronic Engineering, University of Valencia, Burjassot (Valencia) (Spain); Tarnowski, R. [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, PL 02-093 Warszawa (Poland); and others

    2012-05-01

    A study of the dimensions and performance of a single detector of the future neutron detector array NEDA was performed by means of Monte Carlo simulations, using GEANT4. Two different liquid scintillators were evaluated: the hydrogen based BC501A and the deuterated BC537. The efficiency and the probability that one neutron will trigger a signal in more than one detector were investigated as a function of the detector size. The simulations were validated comparing the results to experimental measurements performed with two existing neutron detectors, with different geometries, based on the liquid scintillator BC501.

  14. Measurements of serum glucose using the luciferin/Luciferase system and a liquid scintillation spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Idahl, L.A.; Sandstroem, P.E.; Sehlin, J.

    1986-05-15

    A single-step assay for serum glucose measurements is described. The assay is based on the phosphorylation of D-glucose by glucokinase and the measurement of ATP consumption by firefly luciferase. The luminescence is recorded in an ordinary liquid scintillation spectrometer. The use of stable reagents and a stable final signal (light emission) makes it possible to analyze a large number of samples in each assay run. The assay is of particular value when repeated serum glucose determinations are performed on samples from small laboratory animals.

  15. TDCR and CIEMAT/NIST Liquid Scintillation Methods applied to the Radionuclide Metrology

    Science.gov (United States)

    da Cruz, P. A. L.; da Silva, C. J.; Iwahara, A.; Loureiro, J. S.; De Oliveira, A. E.; Tauhata, L.; Lopes, R. T.

    2016-07-01

    This work presents TDCR and CIEMAT/NIST methods of liquid scintillation implemented in National Institutes of Metrology for activity standardization of radionuclides, which decay by beta emission and electron capture. The computer codes used to calculate the detection efficiency take into account: decay schemes, beta decay theory, quenching parameter evaluation, Poisson statistic model and Monte Carlo simulation for photon and particle interactions in the detection system. Measurements were performed for pure emitters 3H, 14C, 99Tc and for 68Ge/68Ga which decay by electron capture and positron emission, with uncertainties smaller than 1% (k = 1).

  16. TDCR and CIEMAT/NIST liquid scintillation methods applied to the radionuclide metrology

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Paulo A.L. da; Silva, Carlos J. da; Iwahara, Akira; Loureiro, Jamir S.; Oliveira, Antonio E. de; Tauhata, Luiz, E-mail: palcruz@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Lopes, Ricardo T. [Coordenacao de Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2015-07-01

    In this work are presented TDCR and CIEMAT/NIST methods of liquid scintillation implemented in National Institutes of Metrology for activity standardization of radionuclides which decay by beta emission and electron capture. The computer codes to calculate the detection efficiency take into account: decay schemes, beta decay theory, quenching parameter evaluation, Poisson statistic model and Monte Carlo simulation for photon and particle interactions in the detection system. Measurements were performed for {sup 3}H, {sup 14}C, {sup 99}Tc pure beta emitters in a large energy range, and {sup 68}Ge/{sup 68}Ga which decay by electron capture and positron emission, with uncertainties smaller than 1% (k = 1). (author)

  17. Neutron-gamma discrimination employing pattern recognition of the signal from liquid scintillator

    CERN Document Server

    Kamada, K; Ogawa, S

    1999-01-01

    A pattern recognition method was applied to the neutron-gamma discrimination of the pulses from the liquid scintillator, NE-213. The circuit for the discrimination is composed of A/D converter, fast SCA, memory control circuit, two digital delay lines and two buffer memories. All components are packed on a small circuit board and are installed into a personal computer. Experiments using a weak sup 2 sup 5 sup 2 Cf n-gamma source were undertaken to test the feasibility of the circuit. The circuit is of very easy adjustment and, at the same time, of very economical price when compared with usual discrimination circuits, such as the TAC system.

  18. Discrimination of neutrons and {\\gamma}-rays in liquid scintillator based on Elman neural network

    CERN Document Server

    Zhang, Cai-Xun; Zhao, Jian-Ling; Wang, Li; Yu, Xun-Zhen; Zhu, Jing-Jun; Xing, Hao-Yang

    2015-01-01

    A new neutron and {\\gamma} (n/{\\gamma}) discrimination method based on Elman Neural Network (ENN) was put forward to improve the n/{\\gamma} discrimination performance of liquid scintillator (LS). In this study, neutron and {\\gamma} data acquired from EJ-335 which was exposed in Am-Be radiation field was discriminated using ENN. The difference of n/{\\gamma} discrimination performance between using ENN and Back Propagation Neural Network (BPNN) is that ENN gave a improvement over BPNN in n/{\\gamma} discrimination with the increasing increasing of the Figure of Merit (FOM) from 0.907 to 0.953.

  19. Novel determination of protein, fat, and lactose of milk by liquid scintillation counter

    Energy Technology Data Exchange (ETDEWEB)

    Noble, R.C.; Shand, J.H.; West, I.G.

    1981-01-01

    A method for routine determination of protein, fat, and lactose contents of milk is based on the ability of a scintillation counter to measure coloration or opalescence through attenuation of photons emitted from sealed miniature carbon-14 and hydrogen-3 radioactive standards. A series of simplified and accurate analytical procedures enable full advantage to be taken of the automatic facilities on the modern liquid scintillation counter. The methods provide several advantages over existing procedures. Accuracy of quantification was high as assessed by comparing the results with those derived by recommended Kjeldahl, Gerber, and colorimetric procedures for protein, fat, and lactose determinations, respectively.

  20. Data transfer from Beckman LS 5800 liquid scintillation counters to IBM personal computers.

    Science.gov (United States)

    Maan, A C

    1985-09-01

    This communication describes a short routine in BASICA for the IBM-PC, written to collect data from a Beckman liquid scintillation counter. In the form presented here the routine converts incoming bytes into separate lines and saves these lines in a file. There are many possible applications for further use of the data in these files. A few suggestions are given as to the format in which data can be stored and how to process these data automatically after all samples have been counted. The only hardware needed is an asynchronous communications adapter for the IBM-PC and an RS232 cable.

  1. Uncertainty evaluation in tritium activity assay in water by using direct liquid scintillation spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mingote, Raquel Maia; Rocha, Zildete [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Quimica e Radioquimica]. E-mails: mingote@cdtn.br; rochaz@cdtn.br

    2007-07-01

    Tritium-labeled water is often applied to studies in environmental science, hydrology, biology, oil resources and other research areas. In most cases, the tritium activity is determined by using direct liquid scintillation spectrometry without tritium enrichment. A comprehensive uncertainty quantification is so important as accuracy and precision for analysing the results. This paper presents a discussion about the uncertainty propagation law and the partial derivatives method in the tritium assay. It also includes the relations between the tritium activity results and several input parameters. (author)

  2. Rapid determination of gross alpha/beta activity in milk using liquid scintilation counter technique

    Directory of Open Access Journals (Sweden)

    Sas Daniel

    2016-01-01

    Full Text Available Rapid determination of gross alpha and beta emitters in milk by liquid scintillation counter is discussed. This method is based on direct addition of different types of milk into scintillation cocktail and therefore it is very promising for fast determination of alpha/beta activity due to direct alpha and beta separation, measurement in close 4p geometry and without sample treatment. The selected group of radionuclides was chosen with the respect to military significance, radio-toxicity, and possibility of potential misuse. As model radionuclides 241Am, 239Pu, and 90Sr were selected. The Liquid Scintilation Counter Hidex 300 SL equipped with triple-double-coincidence-ratio technique was used for sample measurement. The aim of the work was focused on comparison of different cocktails produced by Hidex and Perkin Elmer, choosing the best cocktail based on our measurement results and adjustment of its appropriate volume. Furthermore, the optimization of ratio between the volume of scintillation cocktail and the volume of urine was investigated with the respect to the model radionuclides. According to the obtained results, the efficiency for alpha emitters was greater than 85% and for beta, greater than 95%. The obtained results allowed this method to be used for rapid determination of gross alpha/beta activity in cases where time is an essence, such as first responders or mass-scale samples, where ordinary means suffer from lack of capacity or simply collapse under the onslaught.

  3. Preparation and performance study of a novel liquid scintillator with mixed solvent as the matrix

    Science.gov (United States)

    Zheng, Zhanlong; Zhu, Jiayi; Luo, Xuan; Xu, Yewei; Zhang, Qianfeng; Zhang, Xing; Bi, Yutie; Zhang, Lin

    2017-04-01

    A novel liquid scintillator with the mixed solvent as the matrix was prepared for obtaining a good comprehensive performance. In this ternary liquid scintillator, the combination of 20% pseudocumene (PC) and 80% linear-alkyl benzene (LAB) by volume was chosen as the mixed solvent, and 2,5-diphenyloxazole (PPO) and 1,4-bis(2-Methylstyryl) benzene (bis-MSB) were as the primary fluor and wavelength shifter, respectively. The optimum prescription was obtained with regard to the light yield. Some characterizations based on the optimal formulation were conducted. The fluorescence emission spectra and wavelength-dependent optical attenuation length of the sample were measured by the fluorescence spectrophotometer and an UV-Vis spectrometer, respectively. The light yield was characterized by adopting the home-made optical platform device. The decay time was tested by adopting the time-correlated single photon counting (TCSPC) technique featured in high dynamic range of several orders of magnitude in light intensity. The experimental test results showed that the sample had a fairly good comprehensive performance.

  4. An easy method for Ra-226 determination in river waters by liquid-scintillation counting

    Science.gov (United States)

    Moreno, H. P.; Vioque, I.; Manjón, G.; García-Tenorio, R.

    1999-01-01

    226Ra activity concentration in river water was determined using a low background liquid scintillation counter. Radium was extracted from the samples as Ra-BaSO4 precipitate which, afterwards, was dissolved with EDTA in ammonia medium. Solution was transferred into a low potassium glass vial and then mixed with a scintillation cocktail. Two different scintillation cocktails were selected for comparison. Efficiency, recovery yield and α/β separation were studied with both liquid scintillation cocktails. One single measurement, made one month after radium separation, allows to calculate the226Ra concentration as well as to assess the presence of alpha contamination of the sample. In the case of negligible interferences,224Ra concentrations can be subsequently evaluated in the same sample by the measurement made just after chemical separation of radium. This method has been applied for the determination of226Ra and224Ra activity concentrations in river water collected from different locations along the Odiel river estuary area (South-west of Spain). The presence of chemical industry, the wastes of which are released into the river, could be connected with radium activity concentration enhancements in the water.

  5. A combined neutron and gamma-ray multiplicity counter based on liquid scintillation detectors

    Science.gov (United States)

    Enqvist, Andreas; Flaska, Marek; Dolan, Jennifer L.; Chichester, David L.; Pozzi, Sara A.

    2011-10-01

    Multiplicity counters for neutron assay have been extensively used in materials control and accountability for nonproliferation and nuclear safeguards. Typically, neutron coincidence counters are utilized in these fields. In this work, we present a measurement system that makes use not only of neutron (n) multiplicity counting but also of gamma-ray ( γ) multiplicity counting and the combined higher-order multiples containing both neutrons and gamma rays. The benefit of this approach is in using both particle types available from the sample, leading to a reduction in measurement times compared with single-particle measurements. We present measurement results of n, γ, nn, nγ, γγ, nnn, nnγ, nγγ and γγγ multiples emitted by Mixed-Oxide (MOX) samples measured at Idaho National Laboratory (INL). The MOX measurement is compared to initial validation of the detection system done using a 252Cf source. The dual radiation measuring system proposed here uses extra measurables to improve the statistics when compared to a neutron-only system and allows for extended analysis and interpretation of sample parameters. New challenges such as the effect of very high intrinsic gamma-ray sources in the case of MOX samples are discussed. Successful measurements of multiple rates can be performed also when using high-Z shielding.

  6. ecCNO Solar Neutrinos: A Challenge for Gigantic Ultra-Pure Liquid Scintillator Detectors

    CERN Document Server

    Villante, F L

    2014-01-01

    Neutrinos produced in the Sun by electron capture reactions on $^{13}{\\rm N}$, $^{15}{\\rm O}$ and $^{17}{\\rm F}$, to which we refer as ecCNO neutrinos, are not usually considered in solar neutrino analysis since the expected fluxes are extremely low. The experimental determination of this sub-dominant component of the solar neutrino flux is very difficult but could be rewarding since it provides a determination of the metallic content of the solar core and, moreover, probes the solar neutrino survival probability in the transition region at $E_\

  7. Measurement of the 8B solar neutrino flux with the KamLAND liquid scintillator detector

    NARCIS (Netherlands)

    Abe, S.; et al., [Unknown; Decowski, M.P.

    2011-01-01

    We report a measurement of the neutrino-electron elastic scattering rate from 8B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5-MeV analysis threshold is 1.49 ± 0.14(stat) ± 0.17(syst) events per kton-day. Interpreted as due t

  8. Development and Mass Production of a Mixture of LAB- and DIN-based Gadolinium-loaded Liquid Scintillator for the NEOS Short-baseline Neutrino Experiment

    CERN Document Server

    Kim, Ba Ro; Jeon, Eun-ju; Joo, Kyung Kwang; Kim, H J; Kim, Hyunsoo; Kim, Jinyu; Kim, Yeongduk; Ko, Youngju; Lee, Jaison; Lee, Jooyoung; Lee, Moohyun; Ma, Kyungju; Oh, Yoomin; Park, Hyangkyu; Park, Kang-soon; Seo, Kyungmin; Seon, Gwang-Min; Siyeon, Kim

    2015-01-01

    A new experiment, which is called as NEOS (NEutrino Oscillation at Short baseline), is proposed on the site of Hanbit reactors at Yonggwang, South Korea, to investigate a reactor antineutrino anomaly. A homogeneous NEOS detector having a 1000-L target volume has been constructed and deployed at the tendon gallery ~25 m away from the reactor core. A linear alkylbenzene (LAB) is used as a main base solvent of the NEOS detector. Furthermore, a di-isopropylnaphthalene (DIN) is added to improve the light output and pulse shape discrimination (PSD) ability. The ratio of LAB to DIN is 90:10. PPO (3 g/L) and bis-MSB (30 mg/L) are dissolved to formulate the mixture of LAB- and DIN-based liquid scintillator (LS). Then, ~0.5% gadolinium (Gd) is loaded into the LS by using the solvent-solvent extraction technique. In this paper, we report the characteristics of Gd-loaded LS (GdLS) for the NEOS detector and the handling during mass production.

  9. Determination of {sup 90}SR in food using extraction chromatography and LSC - Liquid Scintillation Counting

    Energy Technology Data Exchange (ETDEWEB)

    Temba, Eliane S.C.; Amaral, Angela M.; Reis Junior, Aluisio S.; Monteiro, Roberto P.G., E-mail: esct@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG/SERTA), Belo Horizonte, MG (Brazil). Servico de Reator e Tecnicas Analiticas

    2013-07-01

    A methodology for the determination of {sup 90}Sr in food is described. The procedure involved a preliminary freeze-drying of the samples followed by dry-ashing and sample digestion. The separation procedure was carried out using extraction chromatography with Sr Resin, from Eichrom, and {sup 90}Sr was measured by liquid scintillation counting (LSC). A certified reference material, IAEA-375, was analyzed in order to evaluate the reliability of the method, and the results showed good agreement between the measured and certified values. The chemical yield was above 90% and the typical counting efficiency was 82%. The calculated limit of detection was 4.8 x 10{sup -3} Bq g{sup -1}. (author)

  10. Ultra Low Level Tritium Analysis Method Using a Liquid Scintillation Counter

    Energy Technology Data Exchange (ETDEWEB)

    Noh, S. J.; Kim, H. J.; Kim, H.; Lim, H. J.; Lee, M. W.; Jeong, D. H.; Kim, J. K.; Kang, Y. R. [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Nam, S. H. [Inje University, Gimhae, (Korea, Republic of)

    2015-05-15

    To evaluate {sup 3}H concentration in the atmosphere more accurately compared to the conventional methods, the author of this paper intended to suggest more improved analytical methods and derived the elements which might occur during analysis or required improvements. The method suggested in this study is able to reduce the uncertainty and errors which may be existent in evaluating the {sup 3}H concentration of environmental sample s and thus will serve as the best solution in the technical and economic point of view. Liquid Scintillation Counter is the most widely used to analyze ultra-low level {sup 3}H by using CPM / DPM Counting Mode using external radiation source and Spectrum Plot Mode using internal radiation source. In CPM / DPM Counting Mode, multiple samples can be measured by single calibration despite its rather higher background whereas Spectrum Plot Mode requires more time and cost to analyze multiple samples despite its reliability to reduce the contribution of other radionuclides.

  11. Background characterization in a liquid scintillation spectrometer; Caracterizacion del fondo de un espectrometro de centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Los Arcos, J.M.; Jimenez de Mingo, A.

    1995-07-01

    An alternate procedure for background count rate estimation in a liquid scintillation spectrometer is presented, which does not require to measure a blank with similar composition, volume and quench, to the problem sample. The procedure is based on a double linear parameterization which was obtained from a systematic study of the background observed with glass vials, in three different windows, 0 - 20 KeV, 0 - 800 KeV and 0 - 2 MeV, for volume between 2 and 20 mi of three commercial scintillators, Hisafe II, Ultima-Gold and Instagel, and quenching degree in the interval equivalent to 50% - 3% tritium efficiency. This procedure was tested with standard samples of 3H, and led to average discrepancies less than 10% for activity {>=}0,6 Bq, against conventional methods for which the discrepancies are twice on average. (Author) 10 refs.

  12. Theoretical study of structure and stability of small gadolinium carboxylate complexes in liquid scintillator solvents.

    Science.gov (United States)

    Huang, Pin-Wen

    2014-09-01

    The structural properties of three small gadolinium carboxylate complexes in three liquid scintillator solvents (pseudocumene, linear alkylbenzene, and phenyl xylylethane) were theoretically investigated using density functional theory (B3LYP/LC-RECP) and polarizable continuum model (PCM). The average interaction energy between gadolinium atom and carboxylate ligand (E(int)) and the energy difference of the highest singly occupied molecular orbital and lowest unoccupied molecular orbital (Δ(SL)) were calculated to evaluate and compare the relative stability of these complexes in solvents. The calculation results show that the larger (with a longer alkyl chain) gadolinium carboxylate complex has greater stability than the smaller one, while these gadolinium carboxylates in linear alkylbenzene were found to have greater stability than those in the other two solvents.

  13. Laboratory measurement of radioactivity purification for 212Pb in liquid scintillator

    Science.gov (United States)

    Hu, Wei; Fang, Jian; Yu, Bo-Xiang; Zhang, Xuan; Zhou, Li; Cai, Xiao; Sun, Li-Jun; Liu, Wan-Jin; Wang, Lan; Lü, Jun-Guang

    2016-09-01

    Liquid scintillator (LS) has been widely used in past and running neutrino experiments, and is expected also to be used in future experiments. Requirements on LS radio-purity have become higher and higher. Water extraction is a powerful method to remove soluble radioactive nuclei, and a mini-extraction station has been constructed. To evaluate the extraction efficiency and optimize the operation parameters, a setup to load radioactivity to LS and a laboratory scale setup to measure radioactivity using the 212Bi-212Po-208Pb cascade decay have been developed. Experience from this laboratory study will be useful for the design of large scale water extraction plants and the optimization of working conditions in the future. Supported by The Strategic Priority Research Program of the Chinese Academy of Sciences (XDA10010500), Natural Science Foundation of China (11390384)

  14. Determination of {sup 226}Ra and {sup 228}Ra in water by using liquid scintillation spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mingote, Raquel Maia; Gomes, Nilton Carlos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Quimica e Radioquimica], E-mail: mingote@cdtn.br; Gomes, Lorena Pedrosa; Menezes, Maria Angela de B.C. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Reator e Irradiacoes

    2007-07-01

    A procedure for the determination of {sup 226}Ra and {sup 228}Ra in water samples by using liquid scintillation spectrometry was applied. The chemical separation of radium as Ba(Ra)SO{sub 4} was performed by the usual method of coprecipitation with barium carrier. The precipitated was mixed with water, Instagel{sup TM} and Ultima Gold AB{sup TM} scintillation cocktails after the delay time for {sup 226}Ra/{sup 222}Rn radioactive equilibrium. Activities of {sup 226}Ra and {sup 228}Ra were inferred from the alpha and beta counting respectively. It was used the pulse shape analyzer and correction factors for minimizing mutual radiometric interferences. The combined standard uncertainties were evaluated using the law of uncertainty propagation by partial derivatives method. The difficulties of method are discussed. (author)

  15. Attenuation length measurements of liquid scintillator with LabVIEW and reliability evaluation of the device

    CERN Document Server

    Gao, L; Ding, YY; Zhou, L; Wen, LJ; Xie, YG; Wang, ZG; Cai, X; Sun, XL; Fang, J; Xue, Z; Zhang, AW; LÜ, QW; Sun, LJ; Ge, YS; Liu, YB; Niu, SL; Hu, T; Cao, J; LÜ, JG

    2013-01-01

    The attenuation length measuring device was constructed by using oscilloscope and LabVIEW for signal acquisition and processing. The performance of the device has been tested with a variety of ways, the test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent). Besides, the accuracy of the measurement system will decrease by about 17 percent if a filter is used. The attenuation length of gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10 plus or minus 0.35 m where Gd-LS was heavily used in Daya Bay Neutrino Experiment. In addition, one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device, the R-square reached 0.9995. Moreover, three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment.

  16. Calibration of a liquid scintillation counter to assess tritium levels in various samples

    CERN Document Server

    Al-Haddad, M N; Abu-Jarad, F A

    1999-01-01

    An LKB-Wallac 1217 Liquid Scintillation Counter (LSC) was calibrated with a newly adopted cocktail. The LSC was then used to measure tritium levels in various samples to assess the compliance of tritium levels with the recommended international levels. The counter was calibrated to measure both biological and operational samples for personnel and for an accelerator facility at KFUPM. The biological samples include the bioassay (urine), saliva, and nasal tests. The operational samples of the light ion linear accelerator include target cooling water, organic oil, fomblin oil, and smear samples. Sets of standards, which simulate various samples, were fabricated using traceable certified tritium standards. The efficiency of the counter was obtained for each sample. The typical range of the efficiencies varied from 33% for smear samples down to 1.5% for organic oil samples. A quenching curve for each sample is presented. The minimum detectable activity for each sample was established. Typical tritium levels in bio...

  17. Experimental determination of elemental compositions and densities of several common liquid scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Barquero, Leonor, E-mail: l.barquero@ciemat.e [Laboratorio de Metrologia de Radiaciones Ionizantes, CIEMAT, Avenida Complutense, 22, 28040 Madrid (Spain); Los Arcos, Jose M., E-mail: jm.losarcos@ciemat.e [Laboratorio de Metrologia de Radiaciones Ionizantes, CIEMAT, Avenida Complutense, 22, 28040 Madrid (Spain)

    2010-07-15

    New accurate data for the density and the elemental composition of several common liquid scintillators have been determined in this work. These data can be used to correctly determine or calculate the counting efficiency of radio-nuclides as well as to evaluate more accurately the uncertainties in LSC measurements due to variability on the composition of scintillators. The discrepancy between nominal densities at 20{sup o}C and the real densities at 20{sup o}C or 16{sup o}C can reach up to 4% among different batches of commercial scintillators all having the same nominal composition. Also significant differences in the elemental composition of commercial cocktails have been found compared to the nominal values. These differences range from 2% up to 260% depending on the element and the scintillator being measured.

  18. Characterizing a fast-response, low-afterglow liquid scintillator for neutron time-of-flight diagnostics in fast ignition experiments

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Y., E-mail: abe-y@ile.osaka-u.ac.jp; Hosoda, H.; Arikawa, Y.; Nagai, T.; Kojima, S.; Sakata, S.; Inoue, H.; Iwasa, Y.; Iwano, K.; Yamanoi, K.; Fujioka, S.; Nakai, M.; Sarukura, N.; Shiraga, H.; Norimatsu, T.; Azechi, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2014-11-15

    The characteristics of oxygen-enriched liquid scintillators with very low afterglow are investigated and optimized for application to a single-hit neutron spectrometer for fast ignition experiments. It is found that 1,2,4-trimethylbenzene has better characteristics as a liquid scintillator solvent than the conventional solvent, p-xylene. In addition, a benzophenon-doped BBQ liquid scintillator is shown to demonstrate very rapid time response, and therefore has potential for further use in neutron diagnostics with fast time resolution.

  19. Nd loaded liquid scintillator to search for 150Nd neutrinoless double beta decay

    Science.gov (United States)

    Barabanov, I.; Bezrukov, L.; Cattadori, C.; Danilov, N.; di Vacri, A.; Ianni, A.; Nisi, S.; Ortica, F.; Romani, A.; Salvo, C.; Smirnov, O.; Yanovich, E.

    2008-11-01

    The 150Nd is considered one of the most attractive candidate for searching neutrinoless double beta (0νββ-) decay, thanks to its high Q-value (3.367 MeV), that makes the external background issue less significative respect to other isotopes, and favorable computed matrix elements. The isotopic abundance of this isotope in natural neodimium is only 5.6% and up to now, it has been investigated only in low mass experiments. The next step is to increase the sensitivity of the experiments using larger mass of neodymium (10 ton-1 kton). This could be possible with a Nd loaded liquid scintillator (LS). At the Gran Sasso National Laboratory (LNGS), a joint INFN (Istituto Nazionale di Fisica Nucleare) and INR (Institute for Nuclear Research of Moscow) working group has been carrying out since 2001 an R&D activity aiming to develop organic liquid scintillators (LS) doped with metals. The achieved know-how and the satisfactory results obtained both with In and Gd allowed to face the development and production of Nd doped LS. The development of metal doped LS is challenging because the metal has to be embedded in a proper organic system that makes it soluble in an organic solvent minimizing the impact of the metal-organic compound on the optical and scintillation properties of the LS. A further challenge in the case of Nd is the presence of absorption bands of this element in the optical region with a transparent region around 400 nm, which is about at the maximum of the scintillator emission spectrum. A 2.5 1 Nd loaded LS has been produced diluting an originally developed Nd-Carboxylic (Nd-CBX) salt in pseudocumene (PC), the solvent of the Borexino liquid scintillator. The measured light yield, at [Nd] = 6.5 g/1 and [PPO] = 1.5 g/1, is ~ 75% of pure PC at the same fluor concentration (~ 10000 ph/MeV). The Nd doped LS has been tested in a 2 1 quartz cell (wrapped by VM2000 reflector film) having dimensions 5x5x100 cm3. The light propagates in the cell by total internal

  20. COCO, a Compton coincidence experiment to study liquid scintillator response in the 1-20 keV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Peron, M.N. (Laboratoire Primaire des Rayonnements Ionisants, CEA/DAMRI, CE Saclay, BP 52, 91193 Gif-sur-Yvette Cedex (France)); Cassette, P. (Laboratoire Primaire des Rayonnements Ionisants, CEA/DAMRI, CE Saclay, BP 52, 91193 Gif-sur-Yvette Cedex (France))

    1994-12-30

    The use of Liquid Scintillation Counting (LSC) as a fundamental radionuclide standardisation method requires a correct description of the physical phenomena occurring during the LSC process. In that framework, a special point of interest is the description of the liquid scintillator response, especially for low-energy electrons, in a region where this response is known to be non-linear. As there is no simple way to produce monoenergetic electrons in the liquid scintillator, we have simulated these electrons using a Compton interaction coincidence method. Due to the energy conservation law, the selection of the energy of the scattered Compton X-ray photon is equivalent to the selection of the energy of a monoenergetic electron. This paper describes the experimental system and the methods used to analyse the experimental results in order to deduce the statistical distribution of the photons emitted by the scintillator. The effects of some artefacts are discussed, including the accidental coincidences and the influence of cascade Compton interactions. ((orig.))

  1. Deuterated-xylene (xylene-d{sub 10}; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

    Energy Technology Data Exchange (ETDEWEB)

    Becchetti, F.D.; Raymond, R.S.; Torres-Isea, R.O. [Department of Physics, University of Michigan, Ann Arbor, MI 48109 (United States); Di Fulvio, A.; Clarke, S.D.; Pozzi, S.A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Febbraro, M. [Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States)

    2016-06-01

    In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. ×3 in. deuterated-xylene organic liquid scintillator (C{sub 8}D{sub 10}; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C{sub 6}D{sub 6}; NE230, BC537, and EJ315) this scintillator can provide good pulse-shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene-based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is much safer for many applications. In addition EJ301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light-response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective (×10 to ×100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. As we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse-selected beam (as needed for time-of-flight) is not available.

  2. Combustion water purification techniques influence on OBT analysing using liquid scintillation counting method

    Energy Technology Data Exchange (ETDEWEB)

    Varlam, C.; Vagner, I.; Faurescu, I.; Faurescu, D. [National Institute for Cryogenics and Isotopic Technologies, Valcea (Romania)

    2015-03-15

    In order to determine organically bound tritium (OBT) from environmental samples, these must be converted into water, measurable by liquid scintillation counting (LSC). For this purpose we conducted some experiments to determine OBT level of a grass sample collected from an uncontaminated area. The studied grass sample was combusted in a Parr bomb. However usual interfering phenomena were identified: color or chemical quench, chemiluminescence, overlap over tritium spectrum because of other radionuclides presence as impurities ({sup 14}C from organically compounds, {sup 36}Cl as chloride and free chlorine, {sup 40}K as potassium cations) and emulsion separation. So the purification of the combustion water before scintillation counting appeared to be essential. 5 purification methods were tested: distillation with chemical treatment (Na{sub 2}O{sub 2} and KMnO{sub 4}), lyophilization, chemical treatment (Na{sub 2}O{sub 2} and KMnO{sub 4}) followed by lyophilization, azeotropic distillation with toluene and treatment with a volcanic tuff followed by lyophilization. After the purification step each sample was measured and the OBT measured concentration, together with physico-chemical analysis of the water analyzed, revealed that the most efficient method applied for purification of the combustion water was the method using chemical treatment followed by lyophilization.

  3. Liquid Scintillation Counting of Environmental Radioisotopes: A Review of the Impact of Background Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, Matthew; Bernacki, Bruce E.; Erchinger, Jennifer L.; Finn, Erin C.; Fuller, Erin S.; Hoppe, Eric W.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Orrell, John L.; Panisko, Mark E.; Warren, Glen A.; Wright, Michael E.

    2016-03-09

    Liquid scintillation counting (LSC) is a versatile and commonplace method for radiometric measurement of charged particle emitting radionuclides. The LSC method provides utility in a range of environmental science applications including hydrological studies of water transport, anthropogenic releases of radionuclides into the environment, and vertical mixing rates within oceans. Instrumental measurement background is one limiting factor of radiometric measurement sensitivity. As part of the development of a custom low background LSC system located in a shallow underground laboratory at Pacific Northwest National Laboratory, a number of measurement applications of LSC have been considered and are summarized here. The focus is on determining which aspects of such measurements would gain the greatest benefit from the reduction of LSC backgrounds by a factor of 10-100 relative to values reported in the literature. Examples of benefits include lowering the minimum detectable activity, reducing the sample size required, and shortening the elapsed timeline of the processing and analysis sequence. In particular tritium, strontium, and actinium isotopes are examined as these isotopes cover a range of requirements related to the LSC measurement method (e.g., 3H: low energy; Sr: spectral deconvolution; Ac: alpha/beta discrimination).

  4. Spectrum library concept and pulse shape analysis in liquid scintillation counting

    Energy Technology Data Exchange (ETDEWEB)

    Kaihola, L. [Wallac Oy, Turku (Finland)

    1997-03-01

    Wallac introduced in 1990 a new absolute liquid scintillation counting (LSC) method, Digital Overlay Technique (DOT) to correct for quench. This method allows quantization of multilabel samples by referring to library spectra which are generated against chemical and color quench indices at the factory. The libraries can further be expanded to any beta emitter by user with a method called fine tuning, which can be carried out even with a single sample. Spectrum libraries are created over the whole spectrum range of the radionuclide and allow automatic identification of a single label beta emitting radionuclide, called Easy Count method. Another improvement in LSC is commercial introduction of Pulse Shape Analysis (PSA) in 1986 by Wallac. This method recognizes alpha particle decay by pulse shape and leads to excellent sensitivity in alpha counting because most of the background signal in LSC comprises of short or beta like pulses. PSA detects alpha events in the presence of high excess of beta activity over alphas, up to a ratio 100000 to 1. (orig.)

  5. Measurement of neutron dose with an organic liquid scintillator coupled with a spectrum weight function

    Energy Technology Data Exchange (ETDEWEB)

    Kim, E.; Endo, A.; Yamaguchi, Y.; Yoshizawa, M.; Nakamura, T.; Shiomi, T

    2002-07-01

    A dose evaluation method for neutrons in the energy range of a few MeV to 100 MeV has been developed using a spectrum weight function (G-function), which is applied to an organic liquid scintillator of 12.7 cm in diameter and 12.7 cm in length. The G-function that converts the pulse height spectrum of the scintillator into the ambient dose equivalent, H*(10), was calculated by an unfolding method using successive approximation of the response function of the scintillator and the ambient dose equivalent per unit neutron fluence (H*(10) conversion coefficients) of ICRP 74. To verify the response function of the scintillator and the value of H*(10) evaluated by the G-function, pulse height spectra of the scintillator were measured in some different neutron fields, which have continuous energy, monoenergetic and quasi-monoenergetic spectra. Values of H*(10) estimated using the G-function and pulse height spectra of the scintillator were compared with those calculated using neutron energy spectra. These doses agreed with each other. From the results, it was concluded that H*(10) can be evaluated directly from the pulse height spectrum of the scintillator by applying the G-function proposed in this study. (author)

  6. ACID EVAPORATION OF ULTIMA GOLD TM AB LIQUID SCINTILLATION COCKTAIL RESIDUE

    Energy Technology Data Exchange (ETDEWEB)

    Kyser, E.; Fondeur, F.; Crump, S.

    2011-12-21

    Prior analyses of samples from the F/H Lab solutions showed the presence of diisopropylnapthalene (DIN), a major component of Ultima Gold{trademark} AB liquid scintillation cocktail (LSC). These solutions are processed through H-Canyon Tank 10.5 and ultimately through the 17.8E evaporator. Similar solutions originated in SRNL streams sent to the same H Canyon tanks. This study examined whether the presence of these organics poses a process-significant hazard for the evaporator. Evaporation and calorimetry testing of surrogate samples containing 2000 ppm of Ultima Gold{trademark} AB LSC in 8 M nitric acid have been completed. These experiments showed that although reactions between nitric acid and the organic components do occur, they do not appear to pose a significant hazard for runaway reactions or generation of energetic compounds in canyon evaporators. The amount of off-gas generated was relatively modest and appeared to be well within the venting capacity of the H-Canyon evaporators. A significant fraction of the organic components likely survives the evaporation process primarily as non-volatile components that are not expected to represent any new process concerns during downstream operations such as neutralization. Laboratory Waste solutions containing minor amounts of DIN can be safely received, stored, transferred, and processed through the canyon waste evaporator.

  7. Determination of {sup 226}Ra and {sup 224}Ra in sediments samples by liquid scintillation counting

    Energy Technology Data Exchange (ETDEWEB)

    Villa, M. [Facultad de Fisica. Av. Reina Mercedes s/n, apdo 1065, Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, 41080-Sevilla (Spain)]. E-mail: mvilla@us.es; Moreno, H.P. [E.T.S. Arquitectura. Av. Reina Mercedes, 2, Departamento de Fisica Aplicada II, Universidad de Sevilla, 41012-Sevilla (Spain); Manjon, G. [E.T.S. Arquitectura. Av. Reina Mercedes, 2, Departamento de Fisica Aplicada II, Universidad de Sevilla, 41012-Sevilla (Spain)

    2005-10-01

    An experimental procedure has been developed for a rapid determination of the activity concentration of {sup 226}Ra and {sup 224}Ra in sediments by liquid scintillation counting. The importance of the method lies in its application to the measurement of sediments where the Ra-isotopes activity concentration has been increased due to an anthropomorphic enhancement based on releases of naturally occurring radioactive material (NORM). A sample pre-treatment, including a digestion with aqua regia and a precipitation of hydroxides, was applied to samples before the radium extraction, which was made by co-precipitation with barium. Measurements were done in a low background scintillation spectrometer Quantulus 1220, which can separate and detect simultaneously {alpha} and {beta} particles. Additionally, some improvements are suggested for a better {alpha} and {beta} interference correction of the results. The obtaining of radiochemical yields is also improved using {sup 133}Ba as tracer, which decays by emission of conversion electrons and {gamma}-rays; the wide range of radiochemical yields obtained confirms the need of this analyses. The procedure has been applied to the measurement of riverbed sediments from an estuary in the south-west of Spain, affected in the past by direct and indirect phosphogypsum discharges.

  8. Some rules to improve the energy resolution in alpha liquid scintillation with beta rejection

    CERN Document Server

    Aupiais, J; Dacheux, N

    2003-01-01

    Two common scintillating mixtures dedicated to alpha measurements by means of alpha liquid scintillation with pulse shape discrimination were tested: the di-isopropylnaphthalene - based and the toluene-based solvents containing the commercial cocktails Ultima Gold AB trademark and Alphaex trademark. We show the possibility to enhance the resolution up to 200% by using no-water miscible cocktails and by reducing the optical path. Under these conditions, the resolution of about 200 keV can be obtained either by the Tri Carb sup T sup M or by the Perals sup T sup M spectrometers. The time responses, e.g., the time required for a complete energy transfer between the initial interaction alpha particle-solvent and the final fluorescence of the organic scintillator, have been compared. Both cocktails present similar behavior. According to the Foerster theory, about 6-10 ns are required to complete the energy transfer. For both apparatus, the detection limits were determined for alpha emitters. The sensitivity of the...

  9. 210Pb and 210Po determination in environmental samples using liquid scintillation counting and alpha spectrometry

    Science.gov (United States)

    Pérez Sánchez, D.; Martin Sánchez, A.; Jurado Vargas, M.

    2003-01-01

    A simple radiochemical procedure has been developed to determine 210Pb and 210Po in environmental samples from the same matrix. Sediment samples are decomposed by leaching with mineral acids or by microwave digestion, while water samples are pre-concentrated. One part of the resulting solution, spiked with 209Po, is used for 210Po determination by spontaneous deposition onto nickel disks (α-spectrometry). The other part is assayed for 210Pb, separating the Pb either by anion-exchange (sediment samples), or by solvent extraction (water samples). The 210Pb source is finally prepared by precipitation as oxalate and the chemical recovery determined by gravimetry. The 210Pb activity concentration is determined by liquid scintillation. A standard sediment sample supplied by IAEA and spiked water samples were analysed to check the procedure. The 210Pb and 210Po measurements agreed well with the certifications, deviations being less than 10%. The mean recoveries for Pb and Po were (70±12)% and (77±8%) for sediments, and (70±10)% and (81±7)% for waters, respectively.

  10. Liquid scintillation counting methodology for 99Tc analysis. A remedy for radiopharmaceutical waste

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Mumtaz [Univ. of Science and Technology, Gyeongbuk (Korea); Um, Wooyong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-08-13

    This paper presents a new approach for liquid scintillation counting (LSC) analysis of single-radionuclide samples containing appreciable organic or inorganic quench. This work offers better analytical results than existing LSC methods for technetium-99 (99gTc) analysis with significant savings in analysis cost and time. The method was developed to quantify 99gTc in environmental liquid and urine samples using LSC. Method efficiency was measured in the presence of 1.9 to 11,900 ppm total dissolved solids. The quench curve was proved to be effective in the case of spiked 99gTc activity calculation for deionized water, tap water, groundwater, seawater, and urine samples. Counting efficiency was found to be 91.66% for Ultima Gold LLT (ULG-LLT) and Ultima Gold (ULG). Relative error in spiked 99gTc samples was ±3.98% in ULG and ULG-LLT cocktails. Minimum detectable activity was determined to be 25.3 mBq and 22.7 mBq for ULG-LLT and ULG cocktails, respectively. A pre-concentration factor of 1000 was achieved at 100°C for 100% chemical recovery.

  11. Using the transportable, computer-operated, liquid-scintillator fast-neutron spectrometer system

    Energy Technology Data Exchange (ETDEWEB)

    Thorngate, J.H.

    1988-11-01

    When a detailed energy spectrum is needed for radiation-protection measurements from approximately 1 MeV up to several tens of MeV, organic-liquid scintillators make good neutron spectrometers. However, such a spectrometer requires a sophisticated electronics system and a computer to reduce the spectrum from the recorded data. Recently, we added a Nuclear Instrument Module (NIM) multichannel analyzer and a lap-top computer to the NIM electronics we have used for several years. The result is a transportable fast-neutron spectrometer system. The computer was programmed to guide the user through setting up the system, calibrating the spectrometer, measuring the spectrum, and reducing the data. Measurements can be made over three energy ranges, 0.6--2 MeV, 1.1--8 MeV, or 1.6--16 MeV, with the spectrum presented in 0.1-MeV increments. Results can be stored on a disk, presented in a table, and shown in graphical form. 5 refs., 51 figs.

  12. Sensitivity and uncertainty analysis of the simulation of 123I and 54Mn gamma and X-ray emissions in a liquid scintillation vial.

    Science.gov (United States)

    Bignell, L J; Mo, L; Alexiev, D; Hashemi-Nezhad, S R

    2010-01-01

    Radiation transport simulations of the most probable gamma- and X-ray emissions of (123)I and (54)Mn in a three photomultiplier tube liquid scintillation detector have been carried out. A Geant4 simulation was used to acquire energy deposition spectra and interaction probabilities with the scintillant, as required for absolute activity measurement using the triple to double coincidence ratio (TDCR) method. A sensitivity and uncertainty analysis of the simulation model is presented here. The uncertainty in the Monte Carlo simulation results due to the input parameter uncertainties was found to be more significant than the statistical uncertainty component for a typical number of simulated decay events. The model was most sensitive to changes in the volume of the scintillant. Estimates of the relative uncertainty associated with the simulation outputs due to the combined stochastic and input uncertainties are provided. A Monte Carlo uncertainty analysis of an (123)I TDCR measurement indicated that accounting for the simulation uncertainties increases the uncertainty of efficiency of the logical sum of double coincidence by 5.1%. Copyright 2009 Elsevier Ltd. All rights reserved.

  13. Commissioning the SNO+ detector

    Science.gov (United States)

    Descamps, Freija; SNO+ Collaboration

    2016-09-01

    The SNO+ experiment is the successor to the Sudbury Neutrino Observatory (SNO), in which SNO's heavy water is replaced by approximately 780T of liquid scintillator (LAB). The combination of the 2km underground location, the use of ultra-clean materials and the high light-yield of the liquid scintillator means that a low background level and a low energy threshold can be achieved. This creates a new multipurpose neutrino detector with the potential to address a diverse set of physics goals, including the detection of reactor, solar, geo- and supernova neutrinos. A main physics goal of SNO+ is the search for neutrinoless double beta decay. By loading the liquid scintillator with 0.5% of natural Tellurium, resulting in about 1300kg of 130Te (isotopic abundance is slightly over 34%), a competitive sensitivity to the effective neutrino mass can be reached. This talk will present the status of the SNO+ detector, specifically the results and status of the detector commissioning with water.

  14. Digital liquid-scintillation counting and effective pulse-shape discrimination with artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Langrock, Gert; Wiehl, Norbert; Kling, Hans-Otto; Mendel, Matthias; Naehler, Andrea; Tharun, Udo; Eberhardt, Klaus; Trautmann, Norbert; Kratz, Jens Volker [Mainz Univ. (Germany). Inst. fuer Kernchemie; Omtvedt, Jon-Petter [Oslo Univ. (Norway). Dept. of Chemistry; Skarnemark, Gunnar [Chalmers Univ. of Technology, Goeteborg (Sweden)

    2015-05-01

    A typical problem in low-level liquid scintillation (LS) counting is the identification of α particles in the presence of a high background of β and γ particles. Especially the occurrence of β-β and β-γ pile-ups may prevent the unambiguous identification of an α signal by commonly used analog electronics. In this case, pulse-shape discrimination (PSD) and pile-up rejection (PUR) units show an insufficient performance. This problem was also observed in own earlier experiments on the chemical behaviour of transactinide elements using the liquid-liquid extraction system SISAK in combination with LS counting. α-particle signals from the decay of the transactinides could not be unambiguously assigned. However, the availability of instruments for the digital recording of LS pulses changes the situation and provides possibilities for new approaches in the treatment of LS pulse shapes. In a SISAK experiment performed at PSI, Villigen, a fast transient recorder, a PC card with oscilloscope characteristics and a sampling rate of 1 giga samples s{sup -1} (1 ns per point), was used for the first time to record LS signals. It turned out, that the recorded signals were predominantly α β-β and β-γ pile up, and fission events. This paper describes the subsequent development and use of artificial neural networks (ANN) based on the method of 'back-propagation of errors' to automatically distinguish between different pulse shapes. Such networks can 'learn' pulse shapes and classify hitherto unknown pulses correctly after a learning period. The results show that ANN in combination with fast digital recording of pulse shapes can be a powerful tool in LS spectrometry even at high background count rates.

  15. Microfluidic Scintillation Detectors

    CERN Multimedia

    Microfluidic scintillation detectors are devices of recent introduction for the detection of high energy particles, developed within the EP-DT group at CERN. Most of the interest for such technology comes from the use of liquid scintillators, which entails the possibility of changing the active material in the detector, leading to an increased radiation resistance. This feature, together with the high spatial resolution and low thickness deriving from the microfabrication techniques used to manufacture such devices, is desirable not only in instrumentation for high energy physics experiments but also in medical detectors such as beam monitors for hadron therapy.

  16. 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.

  17. Daya Bay Antineutrino Detector Gas System

    CERN Document Server

    Band, H R; Chu, M-C; Heeger, K M; Kwok, M W; Shih, K; Wise, T; Xiao, Q

    2012-01-01

    The Daya Bay Antineutrino Detector gas system is designed to protect the liquid scintillator targets of the antineutrino detectors against degradation and contamination from exposure to ambient laboratory air. The gas system is also used to monitor the leak tightness of the antineutrino detector assembly. The cover gas system constantly flushes the gas volumes above the liquid scintillator with dry nitrogen to minimize oxidation of the scintillator over the five year lifetime of the experiment. This constant flush also prevents the infiltration of radon or other contaminants into these detecting liquids keeping the internal backgrounds low. Since the Daya Bay antineutrino detectors are immersed in the large water pools of the muon veto system, other gas volumes are needed to protect vital detector cables or gas lines. These volumes are also purged with dry gas. Return gas is monitored for oxygen content and humidity to provide early warning of potentially damaging leaks. The design and performance of the Daya...

  18. Astroparticle Physics: Detectors for Cosmic Rays

    Science.gov (United States)

    Salazar, Humberto; Villaseñor, Luis

    2006-09-01

    We describe the work that we have done over the last decade to design and construct instruments to measure properties of cosmic rays in Mexico. We describe the measurement of the muon lifetime and the ratio of positive to negative muons in the natural background of cosmic ray muons at 2000 m.a.s.l. Next we describe the detection of decaying and crossing muons in a water Cherenkov detector as well as a technique to separate isolated particles. We also describe the detection of isolated muons and electrons in a liquid scintillator detector and their separation. Next we describe the detection of extensive air showers (EAS) with a hybrid detector array consisting of water Cherenkov and liquid scintillator detectors, located at the campus of the University of Puebla. Finally we describe work in progress to detect EAS at 4600 m.a.s.l. with a water Cherenkov detector array and a fluorescence telescope at the Sierra Negra mountain.

  19. Evaluation of the ionization quenching correction for several liquid scintillators; Evaluacion de la extincion por ionizacion para diversos liquidos centelleadores

    Energy Technology Data Exchange (ETDEWEB)

    Los Arcos, J. M.; Borras, C.

    1990-07-01

    The most appropriate computational model for the ionization quenching function Q(E) is analyzed for electrons in liquid scintillators. A numerical evaluation of Q(E) from 0.1 keV to 3 MeV which the kB parameter varying between 0.005 and 0.010 cm/MeV is presented for seven scintillators; Toluene, Toluene-Alcohol, PCS, Toluene-CCl4, INSTAGEL, Dioxane-Naphtalene and HISAFE II. The numerical result are summarized as tables of Ieast squares fitting coefficient which make easy the computation of Q(E). (Author)

  20. The air luminescence count for the rapid determination of {sup 222}Rn in a liquid scintillation spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Morita-Murase, Yuko; Murakami, Isao; Homma, Yoshio [Laboratory for Radiopharmaceutical Chemistry, Kyoritsu College of Pharmacy, Tokyo (Japan)

    2001-03-01

    A liquid scintillation spectrometer has been applied to the determination of the counting efficiency for the air luminescence produced by standardized {sup 222}Rn and its daughters. Based on the counting efficiency, known amounts of {sup 222}Rn can be prepared in 3.5 h. Moreover, the {sup 226}Ra source from which {sup 222}Rn is collected does not necessary have to be a standard one. In contrast, the conventional method for preparing known amounts of {sup 222}Rn usually requires a long waiting period (ca. 15-30 days). (author)

  1. Chemical and colour quenching in liquid scintillation counting; Estudio de la extincion quimica y por color en centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Scott, P. E.; Grau, A.

    1987-07-01

    Chemical and colour quenching for H-3 and C-14 was studied. The method includes spectral analysis of colouring agents; methyl red, (4'-dimethylamine-azobenzene 2-carboxylic acid) dimethyl yellow (4'-dimethylamine-azobenzene) and malachite green (methane, bis .(4-dimethyl aminophenyl) - (phenyl)). External standard channels ratio was applied for the liquid scintillation counting of samples. The introduction of an isolated external standard seems to be a strong tool for the correction of chemical and colour quenching curves. (Author) 12 refs.

  2. Radiocarbon dating of archaeological samples (sambaqui) using CO(2) absorption and liquid scintillation spectrometry of low background radiation.

    Science.gov (United States)

    Mendonça, Maria Lúcia T G; Godoy, José M; da Cruz, Rosana P; Perez, Rhoneds A R

    2006-01-01

    Sambaqui means, in the Tupi language, a hill of shells. The sambaquis are archaeological sites with remains of pre-historical Brazilian occupation. Since the sambaqui sites in the Rio de Janeiro state region are older than 10,000 years, the applicability of CO(2) absorption on Carbo-sorb and (14)C determination by counting on a low background liquid scintillation counter was tested. In the present work, sambaqui shells were treated with H(3)PO(4) in a closed vessel in order to generate CO(2). The produced CO(2) was absorbed on Carbo-sorb. On saturation about 0.6g of carbon, as CO(2), was mixed with commercial liquid scintillation cocktail (Permafluor), and the (14)C activity determined by counting on a low background counter, Packard Tricarb 3170 TR/SL, for a period of 1000 mins to enable detection of a radiocarbon age of 22,400 BP. But only samples with ages up to 3500 BP were submitted to the method because the samples had been collected in the municipality of Guapimirim, in archaeological sambaqui-type sites belonging to this age range. The same samples were sent to the (14)C Laboratory of the Centro de Energia Nuclear na Agricultura (CENA/USP) where similar results were obtained.

  3. A scintillator purification system for the Borexino solar neutrino detector

    Science.gov (United States)

    Benziger, J.; Cadonati, L.; Calaprice, F.; Chen, M.; Corsi, A.; Dalnoki-Veress, F.; Fernholz, R.; Ford, R.; Galbiati, C.; Goretti, A.; Harding, E.; Ianni, Aldo; Ianni, Andrea; Kidner, S.; Leung, M.; Loeser, F.; McCarty, K.; McKinsey, D.; Nelson, A.; Pocar, A.; Salvo, C.; Schimizzi, D.; Shutt, T.; Sonnenschein, A.

    2008-03-01

    Purification of the 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector is performed with a system that combines distillation, water extraction, gas stripping, and filtration. This paper describes the principles of operation, design, and construction of that purification system, and reviews the requirements and methods to achieve system cleanliness and leak-tightness.

  4. Test of the electric charge conservation law with Borexino detector

    Science.gov (United States)

    Vishneva, A.; Agostini, M.; Appel, S.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chepurnov, A.; D' Angelo, D.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schonert, S.; Semenov, D.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Unzhakov, E.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2016-02-01

    The new limit on the electron lifetime is obtained from data of the Borexino experiment. The expected signal from the e → γν decay mode is a 256 keV photon detected in liquid scintillator. Because of the extremely low radioactive background level in the Borexino detector it was possible to improve the previous measurement by two orders of magnitude.

  5. Counting efficiency for liquid scintillator systems with a single multiplier phototube; Eficiencia de recuento en espectrometros de centelleo con un solo fotomultiplicador

    Energy Technology Data Exchange (ETDEWEB)

    Grau Malonda, A.; Garcia-Torano, E.

    1984-07-01

    In this paper counting efficiency as a function of a free parameter (the figure of merit) has been computed. The results are applicable to liquid scintillator systems with a single multiplier phototube. Tables of counting efficiency for 62 pure beta emitters are given for figures of merit in the range 0.25 to 50. (Author) 16 refs.

  6. Comparison of calculated spectra for the interaction of photons in a liquid scintillator. Example of Mn-54 835 keV emission

    CSIR Research Space (South Africa)

    Cassette, P

    2006-10-01

    Full Text Available methods require the calculation of the energy spectrum absorbed by the liquid scintillator. For radionuclides emitting X-rays or g-rays, when the energy is greater than a few tens of keV the Compton interaction is important and the absorption is not total...

  7. Development and Studies of Novel Microfabricated Radiation Hard Scintillation Detectors With High Spatial Resolution

    CERN Document Server

    Mapelli, A; Haguenauer, M; Jiguet, S; Renaud, P; Vico Triviño, N

    2011-01-01

    A new type of scintillation detector is being developed with standard microfabrication techniques. It consists of a dense array of scintillating waveguides obtained by coupling microfluidic channels filled with a liquid scintillator to photodetectors. Easy manipulation of liquid scintillators inside microfluidic devices allow their flushing, renewal, and exchange making the active medium intrinsically radiation hard. Prototype detectors have been fabricated by photostructuration of a radiation hard epoxy resin (SU-8) deposited on silicon wafers and coupled to a multi-anode photomultiplier tube (MAPMT) to read-out the scintillation light. They have been characterized by exciting the liquid scintillator in the 200 micrometers thick microchannels with electrons from a 90Sr yielding approximately 1 photoelectron per impinging Minimum Ionizing Particle (MIP). These promising results demonstrate the concept of microfluidic scintillating detection and are very encouraging for future developments.

  8. A simple method to determine bioethanol content in gasoline using two-step extraction and liquid scintillation counting.

    Science.gov (United States)

    Yunoki, Shunji; Saito, Masaaki

    2009-12-01

    A simple method for determining bioethanol content in gasoline containing bioethanol (denoted as E-gasoline in this study) is urgently required. Liquid scintillation counting (LSC) was employed based on the principle that (14)C exists in bioethanol but not in synthetic ethanol. Bioethanol was extracted in two steps by water from E-gasoline containing 3% (E3) or 10% (E10) bioethanol. The (14)C radioactivity was measured by LSC and converted to the amount of bioethanol. The bioethanol content in E-gasoline was determined precisely from the partition coefficient in the extraction and the amount of bioethanol in the water phases: 2.98+/-0.10% for E3 and 10.0+/-0.1% for E10 (means+/-SD; n=3). It appears that this method can be used to determine bioethanol content in E-gasoline quickly and easily.

  9. Low-Afterglow, High-Refractive-Index Liquid Scintillators for Fast-Neutron Spectrometry and Imaging Applications

    CERN Document Server

    Lauck, Ronald; Bromberger, Benjamin; Dangendorf, Volker; Goldberg, Mark B; Mor, Ilan; Tittelmeier, Kai; Vartsky, David

    2009-01-01

    For ion and neutron spectrometry and imaging applications at a high intensity pulsed laser facility, fast liquid scintillators with very low afterglow are required. Furthermore, neutron imaging with fiber (or liquid-core) capillary arrays calls for scintillation materials with high refractive index. To this end, we have examined various combinations of established mixtures of fluors and solvents, that were enriched alternatively with nitrogen or oxygen. Dissolved molecular oxygen is known to be a highly effective quenching agent, that efficiently suppresses the population of the triplet states in the fluor, which are primarily responsible for the afterglow. For measuring the glow curves of scintillators, we have employed the time-correlated single photon counting (TCSPC) technique, characterized by high dynamic range of several orders of magnitude in light intensity. In this paper we outline the application for the fast scintillators, briefly present the scintillation mechanism in liquids, describe our specif...

  10. Attenuation length measurements of a liquid scintillator with LabVIEW and reliability evaluation of the device

    Institute of Scientific and Technical Information of China (English)

    GAO Long; YU Bo-Xiang; DING Ya-Yun; ZHOU Li; WEN Liang-Jian; XIE Yu-Guang; WANG Zhi-Gang

    2013-01-01

    An attenuation length measurement device was constructed using an oscilloscope and LabVIEW for signal acquisition and processing.The performance of the device has been tested in a variety of ways.The test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent).Besides,the accuracy of the measurement system will decrease by about 17 percent if a filter is used.The attenuation length of a gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10±0.35 m where Gd-LS was heavily used in the Daya Bay Neutrino Experiment.In addition,one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device,the R-square reached 0.9995.Moreover,three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment.

  11. Role of quenching on alpha/beta separation in liquid scintillation counting for several high capacity cocktails

    Energy Technology Data Exchange (ETDEWEB)

    Pujol, L.; Sanchez-Cabeza, J.-A. [Universidad Autonoma de Barcelona (Spain). Facultad de Ciencias

    1997-04-01

    The optimization of alpha/beta separation in liquid scintillation using pulse shape analysis is convenient for the simultaneous determination of alpha and beta emitters in natural water and other samples. In this work, alpha/beta separation was studied for different scintillant/vial combinations and it was observed that both the optimum pulse shape discrimination level and the total interference value (that is, the summed relative interference between alpha and beta spectra) were dependent on the sample quenching and independent of the scintillant/vial combination. These results provide a simple method for modifying the counting configuration, such as a change in the cocktail, vial or sample characteristics, without the need to perform exhaustive parameter optimizations. Also, it was observed that, for our counting conditions, the combination of Ultima Gold AB scintillation cocktail with Zinsser low diffusion vials presented the lowest total interference, namely 0.94 {+-} 0.28%, which is insignificant for the counting of environmental samples. (Author).

  12. Counting efficiencies by liquid scintillation counting. Single isomeric transitions; Eficiencia de recuento por centelleo liquido. Transiciones isomericas simples

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    1995-07-01

    In this work we present liquid scintillation counting efficiency tables for several radionuclides with single isomeric transitions, in which electron conversion and gamma emission processes are competitive. We study the radionuclides: 58mCo, 77mSe, 79mBr, 87mSr, S9mY, 93mNb, 103mRh, 107mAg, 109mAg, 113mIn, 131mXe, I33mXe, 135raBa, 137mBa, 167raEr, for two different scintillators, Ultima-Gold and Insta-Gel. We consider volumes of 10 and 15 mL for Ultima Gold, and 15 mL for Insta-Gel. (Author) 18 refs.

  13. Optics study of liquid scintillation counting systems; Estudio de la Optica en sistemas de medida por centelle liquido

    Energy Technology Data Exchange (ETDEWEB)

    Duran Ramiro, M. T.; Garcia-Torano, E.

    2005-07-01

    Optics is a key issue in the development of any liquid scintillation counting (LSC) system. Light emission in the scintillating solution, transmission through the vial and reflector design are some aspects that need to be considered in detail. This paper describes measurements and calculations carried out to optimise these factors for the design of a new family of LSC counters. Measurements of the light distribution emitted by a scintillation vial were done by autoradiographs of cylindrical vials made of various materials and results were compared to those obtained by direct measurements of the light distribution made by scanning the vial with a photomultiplier tube. Calculations were also carried out to study the light transmission in the vial and the optimal design of the reflector for a system with one photomultiplier tube. (Author)

  14. Attenuation length measurements of a liquid scintillator with LabVIEW and reliability evaluation of the device

    Science.gov (United States)

    Gao, Long; Yu, Bo-Xiang; Ding, Ya-Yun; Zhou, Li; Wen, Liang-Jian; Xie, Yu-Guang; Wang, Zhi-Gang; Cai, Xiao; Sun, Xi-Lei; Fang, Jian; Xue, Zhen; Zhang, Ai-Wu; Lü, Qi-Wen; Sun, Li-Jun; Ge, Yong-Shuai; Liu, Ying-Biao; Niu, Shun-Li; Hu, Tao; Cao, Jun; Lü, Jun-Guang

    2013-07-01

    An attenuation length measurement device was constructed using an oscilloscope and LabVIEW for signal acquisition and processing. The performance of the device has been tested in a variety of ways. The test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent). Besides, the accuracy of the measurement system will decrease by about 17 percent if a filter is used. The attenuation length of a gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10±0.35 m where Gd-LS was heavily used in the Daya Bay Neutrino Experiment. In addition, one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device, the R-square reached 0.9995. Moreover, three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment.

  15. The implications of particle energy and acidic media on gross alpha and gross beta determination using liquid scintillation

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Garcia, D. [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain); Llaurado, M., E-mail: montse.llaurado@ub.edu [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain); Rauret, G. [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain)

    2012-04-15

    The interaction of humans with radioactivity present in the environment from natural and artificial sources necessitates an evaluation of its risk on human health. Gross alpha and gross beta activities can provide a rapid evaluation of the radioactive content of a sample and can be simultaneously determined by using liquid scintillation counters. However, calibration of the liquid scintillation counter is required and is affected by many factors, such as particle energy and the acidity of the media. This study investigates what effect the particle energy used for calibration has on misclassification and how to account for this misclassification in routine measurements. The variability in measurement produced by the final pH, as well as any acids used in sample treatment, was also studied. These results showed that the most commonly used acid for these types of analyses, HNO{sub 3}, produced a high amount of misclassifications at very low pH. The results improved when HCl was used to adjust the sample to low pH. - Highlights: Black-Right-Pointing-Pointer We study the effect of alpha and beta energies on PSA optimisation. Black-Right-Pointing-Pointer The optimum PSA shifts to higher values as the alpha energy increases. Beta energies do not affect it. Black-Right-Pointing-Pointer We study the effect of pH on the simultaneous determination of gross alpha/beta activities. Black-Right-Pointing-Pointer HNO{sub 3} produces a high amount of misclassification at very low pH. Black-Right-Pointing-Pointer The results improve when HCl is used to adjust the sample to low pH.

  16. Measurements of the densities, isobaric thermal expansion coefficients and isothermal compressibilities of linear alkylbenzene in large liquid scintillator detectors

    CERN Document Server

    Zhou, Xiang; Liu, Qian; Zhang, Zhenyu; Ding, Yayun; Zhou, Li; Cao, Jun

    2014-01-01

    We report the measurements of the densities of linear alkylbenzene at three temperatures over 4 to 23 Celsius degree with pressures up to 10 MPa. The measurements have been analysed to yield the isobaric thermal expansion coefficients and, so far for the first time, isothermal compressibilities of linear alkylbenzene.

  17. Prospects of detecting the QCD phase transition in the Galactic supernova neutrino burst with 20-kton scale liquid scintillation detectors

    Science.gov (United States)

    Petkov, V. B.

    2016-06-01

    The supernova explosion in the Galaxy is a rare event; that is why the comprehensive study of the next one has absolute priority for the low-energy neutrino astronomy. Because the detailed explosion mechanism has not been unambiguously identified yet and the surrounding matter envelope is opaque for photons, the neutrinos only can give information about physical conditions, dynamics of the collapse, and the SN mechanism. Furthermore, neutrinos could potentially reveal new physics (e.g. QCD phase transition) operating deep in the stellar core.

  18. The Daya Bay Antineutrino Detector Filling System and Liquid Mass Measurement

    CERN Document Server

    Band, H R; Draeger, E; Heeger, K M; Hinrichs, P; Lewis, C A; Mattison, H; McFarlane, M C; Webber, D M; Wenman, D; Wang, W; Wise, T; Xiao, Q

    2013-01-01

    The Daya Bay Reactor Neutrino Experiment has measured the neutrino mixing angle \\theta_{13} to world-leading precision. The experiment uses eight antineutrino detectors filled with 20-tons of gadolinium-doped liquid scintillator to detect antineutrinos emitted from the Daya Bay nuclear power plant through the inverse beta decay reaction. The precision measurement of sin^{2}2\\theta_{13} relies on the relative antineutrino interaction rates between detectors at near (400 m) and far (roughly 1.8 km) distances from the nuclear reactors. The measured interaction rate in each detector is directly proportional to the number of protons in the liquid scintillator target. A precision detector filling system was developed to simultaneously fill the three liquid zones of the antineutrino detectors and measure the relative target mass between detectors to <0.02%. This paper describes the design, operation, and performance of the system and the resulting precision measurement of the detectors' target liquid masses.

  19. p-Terphenyl: An alternative to liquid scintillators for neutron detection

    Energy Technology Data Exchange (ETDEWEB)

    Sardet, A., E-mail: alix.sardet@cea.fr [CEA, DAM, DIF, F-91297 Arpajon (France); Varignon, C.; Laurent, B.; Granier, T. [CEA, DAM, DIF, F-91297 Arpajon (France); Oberstedt, A. [CEA, DAM, DIF, F-91297 Arpajon (France); Fundamental Physics, Chalmers University of Technology, S-41296 Göteborg (Sweden)

    2015-08-21

    A detailed characterization of doped paraterphenyl (p-Terphenyl) neutron detectors was obtained by means of γ-sources and a {sup 252}Cf fission chamber. The intrinsic timing resolution, the energy resolution up to 2 MeV{sub ee}, and the electron-equivalent energy calibration were determined using γ-sources. The neutron time-of-flight spectrum from the spontaneous fission of {sup 252}Cf provided information on the proton energy calibration, the light output function, and the intrinsic neutron detection efficiency between 0 and 8 MeV for a threshold of 250 keV. Measurements of the latter were also performed using monoenergetic neutron beams. The applied experimental methods were cross-checked using two BC501A scintillation detectors, which were previously calibrated at the Physikalisch-Technische Bundesanstalt in Braunschweig, Germany. Results were compared to Monte-Carlo simulations performed using NRESP7 and NEFF7 codes.

  20. Standardization of 137mCs+137mBa by Liquid Scintillation; Calibracion de 137Cs+137mBa por Centelleo Liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L.; Los Arcos, J.M.; Grau, A.

    1995-07-01

    A procedure for the preparation of a stable, homogeneous solution of 137Cs+''137mBa, for use in liquid scintillation measurements, is described. Its count rate stability and spectral time evolution has been followed for several weeks. The solution has been standardised by the CIEMAT/NIST method in both Ultima-Gold and Insta-Gel, to a combined uncertainty lower than 0,51 % (k=l). (Author) 5 refs.

  1. Modular detector for deep underwater registration of muons and muon groups

    Science.gov (United States)

    Demianov, A. I.; Sarycheva, L. I.; Sinyov, N. B.; Varadanyan, I. N.; Yershov, A. A.

    1985-01-01

    Registration and identification of muons and muon groups penetrating into the ocean depth, can be performed using a modular multilayer detector with high resolution bidimensional readout - deep underwater calorimeter (project NADIR). Laboratory testing of a prototype sensor cell with liquid scintillator in light-tight casing, testifies to the practicability of the full-scale experiment within reasonable expences.

  2. A compact ultra-clean system for deploying radioactive sources inside the KamLAND detector

    NARCIS (Netherlands)

    Banks, T.I.; Freedman, S.J.; Wallig, J.; Ybarrolaza, N.; Gando, A.; Gando, Y.; Ikeda, H.; Inoue, K.; Kishimoto, Y.; Koga, M.; Mitsui, T.; Nakamura, K.; Shimizu, I.; Shirai, J.; Suzuki, A.; Takemoto, Y.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B.D.; Yoshida, H.; Yoshida, S.; Kozlov, A.; Grant, C.; Keefer, G.; Piepke, A.; Bloxham, T.; Fujikawa, B.K.; Han, K.; Ichimura, K.; Murayama, H.; O'Donnell, T.; Steiner, H.M.; Winslow, L.A.; Dwyer, D.A.; McKeown, R.D.; Zhang, C.; Berger, B.E.; Lane, C.E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J.G.; Matsuno, S.; Sakai, M.; Horton-Smith, G.A.; Downum, K.E.; Gratta, G.; Efremenko, Y.; Perevozchikov, O.; Karwowski, H.J.; Markoff, D.M.; Tornow, W.; Heeger, K.M.; Detwiler, J.A.; Enomoto, S.; Decowski, M.P.

    2015-01-01

    We describe a compact, ultra-clean device used to deploy radioactive sources along the vertical axis of the KamLAND liquid-scintillator neutrino detector for purposes of calibration. The device worked by paying out and reeling in precise lengths of a hanging, small-gauge wire rope (cable); an assort

  3. Validation of a procedure for the analysis of (226)Ra in naturally occurring radioactive materials using a liquid scintillation counter.

    Science.gov (United States)

    Kim, Hyuncheol; Jung, Yoonhee; Ji, Young-Yong; Lim, Jong-Myung; Chung, Kun Ho; Kang, Mun Ja

    2017-01-01

    An analytical procedure for detecting (226)Ra in naturally occurring radioactive materials (NORMs) using a liquid scintillation counter (LSC) was developed and validated with reference materials (zircon matrix, bauxite matrix, coal fly ash, and phosphogypsum) that represent typical NORMs. The (226)Ra was released from samples by a fusion method and was separated using sulfate-coprecipitation. Next, a (222)Rn-emanation technique was applied for the determination of (226)Ra. The counting efficiency was 238 ± 8% with glass vials. The recovery for the reference materials was 80 ± 11%. The linearity of the method was tested with different masses of zircon matrix reference materials. Using 15 types of real NORMs, including raw materials and by-products, this LSC method was compared with γ-spectrometry, which had already been validated for (226)Ra analysis. The correlation coefficient for the results from the LSC method and γ-spectrometry was 0.993 ± 0.058.

  4. Development of time-of-flight neutron detector with fast-decay and low-afterglow scintillator for fast ignition experiment

    Directory of Open Access Journals (Sweden)

    Nagai T.

    2013-11-01

    Full Text Available A fast-decay and low-afterglow liquid scintillator was developed for the fast ignition experiment at the Institute of Laser Engineering (ILE. The liquid scintillator was coupled to a gated photomultiplier (PMT, and the gating performance under high-intensity γ-rays was experimentally checked. In 2010, a detector with a high detection efficiency of 10−4 was developed and installed in this experiment. The neutron yield in the fast heating experiment was successfully measured using this detector.

  5. UCSB High Energy Physics Detector R&D Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Monreal, Benjamin [Univ. of California, Santa Barbara, CA (United States); Stuart, David [Univ. of California, Santa Barbara, CA (United States); Nelson, Harry [Univ. of California, Santa Barbara, CA (United States)

    2017-06-30

    The R&D efforts of the UCSB Detector R&D program in the 2015--2017 period are reported. These were to develop a liquid scintillator based detector to be used for characterizing radioactive impurities in samples for rapid and effective screening of low background materials for direct dark matter detection experiments; complete engineering and simulation work investigating the feasibility of constructing large detectors in salt caverns; and provide engineering innovation for development of new ideas.

  6. Comparison of the quantulus 1220 and 300SL liquid scintillation counters for the analysis of {sup 222}Rn in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Cheol; Jung, Yoon Hee; Lee, Wanno; Choi, Guen Sik; Chung, Kun Ho; Kang, Mun Ja [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-12-15

    Liquid scintillation counters (LSCs) are commonly used as an analytical method for detecting {sup 222}Rn in groundwater because they involve a simple sample pretreatment and allow high throughout with an autosampler. The Quantulus 1220 is the best-selling LSC in Korea, but its production was stopped. Recently, a new type of LSC, the 300SL, was introduced. In this study, the 300SL was compared with the Quantulus 1220 in order to evaluate the ability of each apparatus to detect {sup 222}Rn in groundwater. The Quantulus 1220 and 300SL were used to detect the presence of {sup 222}Rn. Radon gas was extracted from a groundwater sample using a water-immiscible cocktail in a LSC vial. The optimal analytical conditions for each LSC were determined using a {sup 222}Rn calibration source prepared with a {sup 226}Ra source. The optimal pulse shape analysis level for alpha and beta separation was 80 for the Quantulus 1220, and the corresponding pulse length index was 12 in the 300SL. The counting efficiency of the Quantulus 1220 for alpha emissions was similar to that of the 300SL, but the background count rate of the Quantulus 1220 was 10 times lower than that of the 300SL. The minimum detectable activity of the Quantulus 1220 was 0.08 Bq·L{sup -,} while that of the 300SL was 0.20 Bq·L{sup -1}. The analytical results regarding {sup 222}Rn in groundwater were less than 10% different between these LSCs. The 300SL is an LSC that is comparable to the Quantulus 1220 for detecting {sup 222}Rn in groundwater. Both LSCs can be applied to determine the levels of {sup 222}Rn in groundwater under the management of the Ministry of Environment.

  7. Search for Majorana neutrinos with the SNO+ detector at SNOLAB

    Science.gov (United States)

    Maio, A.; SNO+ Collaboration

    2015-02-01

    The SNO+ experiment is adapting the Sudbury Neutrino Observatory (SNO) detector, in order to use isotope-loaded liquid scintillator as the active medium. SNO+ has multiple scientific goals, the main one being the search for neutrinoless double beta decay, the most promising signature for the possible Majorana character of neutrinos and for the absolute neutrino mass. Measurements of neutrinos from the Sun, the Earth, Supernovae and nuclear reactors are additional goals of the experiment. The detector consists of a 12m diameter spherical vessel, filled with 780 tonnes of Tellurium-loaded liquid scintillator, and surrounded by about 9500 PMTs. It is shielded by a large volume of ultra-pure water and the underground location at SNOLAB, Canada. This talk will review the Physics goals and current status of SNO+.

  8. Liquid scintillation counting efficiency in three photomultiplier systems. Pure electron capture; Eficiencia de recuento por centelleo liquido en sistemas con tres fotomultiplicadores. Captura electronica pura

    Energy Technology Data Exchange (ETDEWEB)

    Los Arcos, J. M.; Grau Carles, A.; Grau Malonda, A.

    1990-07-01

    The tables of counting efficiency as a function of the figure of merit for a liquid scintillation counting system working with three phototubes are presented. The evaluation has been carried out for a Toluene-based scintillator with 5, 10 and 15 ml column, and 19 different radionuclides decaying by pure electron capture: 37Ar 41Ca, 49V, 53 Mn, 55Fe, 59Ni, 68Ge 7iGe, 82Sr, 97Tc, 118Te, 131CS, 137La, 140Ca, 157Tb, 165Er, 193Pt, 194Hg, 205Pb. (Author) 22 refs.

  9. SCINFI, a program to calculate the standardization curve in liquid scintillation counting; SCINFI, un programa para calcular la curva de calibracion eficiencia-extincion en centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    1984-07-01

    A code, SCINFI, was developed, written in BASIC, to compute the efficiency- quench standardization curve for any radionuclide. The program requires the standardization curve for 3H and the polynomial relations between counting efficiency and figure of merit for both 3H and the problem (e.g. 14{sup C}). The program is applied to the computation of the efficiency-quench standardization curve for 14{sup c}. Five different liquid scintillation spectrometers and two scintillator solutions have bean checked. The computation results are compared with the experimental values obtained with a set of 14{sup c} standardized samples. (Author)

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

    Institute of Scientific and Technical Information of China (English)

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

    2013-01-01

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

  11. Evaluation of different parameters affecting the liquid scintillation spectrometry measurement of gross alpha and beta index in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Palomo, M. [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Tarragona (Spain); Villa, M. [Centro de Investigacion, Tecnologia e Innovacion. Servicio Radioisotopos. Universidad de Sevilla (Spain); Casacuberta, N. [Institut de Ciencia i Tecnologia Ambientals-Departament de Fisica, Universitat Autonoma de Barcelona. Spain (Spain); Penalver, A.; Borrull, F. [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Tarragona (Spain); Aguilar, C., E-mail: carme.aguilar@urv.cat [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Tarragona (Spain)

    2011-09-15

    Liquid scintillation spectrometry is a fast competitive technique for the simultaneous evaluation of gross alpha and beta indexes. However, the implementation of this technique should not be considered as straightforward, and the pre-concentration methods to decrease the detection limit together with quenching and alpha, and beta crossover corrections should be carefully chosen according to the needs of the laboratory. Both aspects are being approached in this work as to find an easy and robust method for alpha/beta measurement in water samples, taking into account the quenching and alpha/beta crossover interferences effects. Results showed that most of the pre-concentration methods increased the quenching in the measurement, although HNO{sub 3} 0.05 M points to be the best solution for pre-concentration and re-dissolution of the sample as converges into low quenching and maximum recovery. Subsequently, in the measurement of water samples with different conductivities, the analysis of the raw counts to obtain gross alpha and beta indexes was carried out using different approaches to implement quenching and interference corrections. If quenching and salt content in the sample are relatively low, interference and quenching-efficiency corrections do not improve the accuracy of the results within the usual precision assumed for a result of gross alpha and beta index (25%). Special attention must be paid when corrections are applied to high quenched or saline samples and when alpha and beta activities values are different in several orders of magnitude. - Highlights: > Developed method for simultaneously quantifying gross alpha and gross beta indexes based on LSC was as accurate and precise as the results obtained from methods based on gas proportional counting and ZnS alpha counting. > Alpha/beta crossover and/or quenching corrections were applied and the results obtained did not improve accuracy within 25% dispersion, a widespread acceptance limit for gross alpha and

  12. Determination of the 10Be half-life by multicollector ICP-MS and liquid scintillation counting

    Science.gov (United States)

    Chmeleff, Jérôme; von Blanckenburg, Friedhelm; Kossert, Karsten; Jakob, Dieter

    2010-01-01

    A new method was designed and used for determining the half-life of the isotope 10Be. The method is based on (1) accurate 10Be/ 9Be measurements of 9Be-spiked solutions of a 10Be-rich master solution using multicollector ICP mass spectrometry (MC-ICP-MS) and (2) liquid scintillation counting (LSC) using the CIEMAT/NIST method for determining the activity concentrations of the solutions whose 10Be concentrations were determined by mass spectrometry. Important requirements for the success of this approach (a) was the previous coating of glass ampoules filled for counting experiments with 9Be, thereby reducing the risk of the adsorptive loss of 10Be; (b) the removal of Boron from solutions to be measured by MC-ICP-MS by cation chromatography without the introduction of mass fractionation and (c) the accurate determination of the mass bias of 10Be/ 9Be measurements by ICP-MS which are always affected by the space-charge effect. The mass bias factor was determined to be 1.1862 ± 0.071 for 10Be/ 9Be from careful fitting and error propagation of ratios of measured Li, B, Si, Cr, Fe, Cu, Sr, Nd, Hf, Tl and U standard solutions of known composition under the same measurement conditions. Employing this factor, an absolute 10Be/ 9Be ratio of 1.464 ± 0.014 was determined for a first dilution of the 10Be-rich master solution. This solution is now available as an absolute Be ratio standard in AMS measurements. Finally, a half-life of (1.386 ± 0.016) My (standard uncertainty) was calculated. This value is much more precise than previous estimates and was derived from a fully independent set of experiments. In a parallel, fully independent study using the same master solution, Korschinek et al. [35] have determined a half-life of (1.388 ± 0.018) My. The combined half-life and uncertainty amounts to (1.387 ± 0.012) My. We suggest the use of this value in nuclear studies and in studies that make use of cosmogenic 10Be in environmental and geologic samples.

  13. A rapid method for the simultaneous determination of gross alpha and beta activities in water samples using a low background liquid scintillation counter

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Cabeza, J.A.; Pujol, Ll. [Universitat Autonoma de Barcelona, Bellaterra (Spain)

    1995-05-01

    The radiological examination of water requires a rapid screening technique that permits the determination of the gross alpha and beta activities of each sample in order to decide if further radiological analyses are necessary. In this work, the use of a low background liquid scintillation system (Quantulus 1220) is proposed to simultaneously determine the gross activities in water samples. Liquid scintillation is compared to more conventional techniques used in most monitoring laboratories. In order to determine the best counting configuration of the system, pulse shape discrimination was optimized for 6 scintillant/vial combinations. It was concluded that the best counting configuration was obtained with the scintillation cocktail Optiphase Hisafe 3 in Zinsser low diffusion vials. The detection limits achieved were 0.012 Bq L{sup -1} and 0.14 Bq L{sup {minus}1} for gross alpha and beta activity respectively, after a 1:10 concentration process by simple evaporation and for a counting time of only 360 min. The proposed technique is rapid, gives spectral information, and is adequate to determine gross activities according to the World Health Organization (WMO) guideline values.

  14. 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)

  15. Automated Calibration System for a High-Precision Measurement of Neutrino Mixing Angle $\\theta_{13}$ with the Daya Bay Antineutrino Detectors

    CERN Document Server

    Liu, J; Carr, R; Dwyer, D A; Gu, W Q; Li, G S; Qian, X; McKeown, R D; Tsang, R H M; Wang, W; Wu, F F; Zhang, C

    2013-01-01

    We describe the automated calibration system for the antineutrino detectors in the Daya Bay Neutrino Experiment. This system consists of 24 identical units instrumented on 8 identical 20-ton liquid scintillator detectors. Each unit is a fully automated robotic system capable of deploying an LED and various radioactive sources into the detector along given vertical axes. Selected results from performance studies of the calibration system are reported.

  16. Automated calibration system for a high-precision measurement of neutrino mixing angle θ{sub 13} with the Daya Bay antineutrino detectors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J., E-mail: jianglai.liu@sjtu.edu.cn [Department of Physics, Shanghai Jiao Tong University, Shanghai (China); Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Cai, B.; Carr, R. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Dwyer, D.A. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Gu, W.Q.; Li, G.S. [Department of Physics, Shanghai Jiao Tong University, Shanghai (China); Qian, X. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Brookhaven National Laboratory, Upton, NY (United States); McKeown, R.D. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Department of Physics, College of William and Mary, Williamsburg, VA (United States); Tsang, R.H.M. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Wang, W. [Department of Physics, College of William and Mary, Williamsburg, VA (United States); Wu, F.F. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Zhang, C. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Brookhaven National Laboratory, Upton, NY (United States)

    2014-06-01

    We describe the automated calibration system for the antineutrino detectors in the Daya Bay Neutrino Experiment. This system consists of 24 identical units instrumented on 8 identical 20-ton liquid scintillator detectors. Each unit is a fully automated robotic system capable of deploying an LED and various radioactive sources into the detector along given vertical axes. Selected results from performance studies of the calibration system are reported.

  17. Development and Prototyping of the PROSPECT Antineutrino Detector

    Science.gov (United States)

    Commeford, Kelley; Prospect Collaboration

    2017-01-01

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

  18. The Electronics and Data Acquisition System for the DarkSide-50 Veto Detectors

    CERN Document Server

    Agnes, P; Albuquerque, I F M; Alexander, T; Alton, A K; Arisaka, K; Back, H O; Baldin, B; Biery, K; Bonfini, G; Bossa, M; Bottino, B; Brigatti, A; Brodsky, J; Budano, F; Bussino, S; Cadeddu, M; Cadoni, M; Calaprice, F; Canci, N; Candela, A; Cao, H; Cariello, M; Carlini, M; Catalanotti, S; Cavalcante, P; Chepurnov, A; Cocco, A G; Covone, G; Crippa, L; D'Angelo, D; D'Incecco, M; Davini, S; De Cecco, S; De Deo, M; De Vincenzi, M; Derbin, A; Devoto, A; Di Eusanio, F; Di Pietro, G; Edkins, E; Empl, A; Fan, A; Fiorillo, G; Fomenko, K; Foster, G; Franco, D; Gabriele, F; Galbiati, C; Giganti, C; Goretti, A M; Granato, F; Grandi, L; Gromov, M; Guan, M; Guardincerri, Y; Hackett, B R; Herner, K R; Hungerford, E V; Ianni, Aldo; Ianni, Andrea; James, I; Jollet, C; Keeter, K; Kendziora, C L; Kobychev, V; Koh, G; Korablev, D; Korga, G; Kubankin, A; Li, X; Lissia, M; Lombardi, P; Luitz, S; Ma, Y; Machulin, I N; Mandarano, A; Mari, S M; Maricic, J; Marini, L; Martoff, C J; Meregaglia, A; Meyers, P D; Miletic, T; Milincic, R; Montanari, D; Monte, A; Montuschi, M; Monzani, M E; Mosteiro, P; Mount, B J; Muratova, V N; Musico, P; Napolitano, J; Nelson, A; Odrowski, S; Orsini, M; Ortica, F; Pagani, L; Pallavicini, M; Pantic, E; Parmeggiano, S; Pelczar, K; Pelliccia, N; Pocar, A; Pordes, S; Pugachev, D A; Qian, H; Randle, K; Ranucci, G; Razeto, A; Reinhold, B; Renshaw, A L; Riffard, Q; Romani, A; Rossi, B; Rossi, N; Rountree, S D; Sablone, D; Saggese, P; Saldanha, R; Sands, W; Sangiorgio, S; Savarese, C; Segreto, E; Semenov, D A; Shields, E; Singh, P N; Skorokhvatov, M D; Smirnov, O; Sotnikov, A; Stanford, C; Suvorov, Y; Tartaglia, R; Tatarowicz, J; Testera, G; Tonazzo, A; Trinchese, P; Unzhakov, E V; Vishneva, A; Vogelaar, R B; Wada, M; Walker, S; Wang, H; Wang, Y; Watson, A W; Westerdale, S; Wilhelmi, J; Wojcik, M M; Xiang, X; Xu, J; Yang, C; Yoo, J; Zavatarelli, S; Zec, A; Zhong, W; Zhu, C; Zuzel, G

    2016-01-01

    DarkSide-50 is a detector for dark matter candidates in the form of weakly interacting massive particles (WIMPs). It utilizes a liquid argon time projection chamber (LAr TPC) for the inner main detector. The TPC is surrounded by a liquid scintillator veto (LSV) and a water Cherenkov veto detector (WCV). The LSV and WCV, both instrumented with PMTs, act as the neutron and cosmogenic muon veto detectors for DarkSide-50. This paper describes the electronics and data acquisition system used for these two detectors.

  19. Comparison of analysis techniques by liquid scintillation and Cerenkov Effect for {sup 40}K quantification in aqueous samples; Comparacion de las tecnicas de analisis por centelleo liquido y efecto Cerenkov para la cuantificacion {sup 40}K en muestras acuosas

    Energy Technology Data Exchange (ETDEWEB)

    Miranda C, L.; Davila R, J. I.; Lopez del R, H.; Mireles G, F., E-mail: lilimica20@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-09-15

    In this work the counting by liquid scintillation and Cerenkov Effect to quantify {sup 40}K in aqueous samples was used. The performance of both techniques was studied by comparing the response of three commercial liquid scintillation OptiPhase HiSafe 3, Ultima Gold Ab and OptiPhase TriSafe, the vial type and presentation conditions of the sample for counting. In liquid scintillation, the ability to form homogeneous mixtures depended on the ionic strength of the aqueous solutions. The scintillator OptiPhase HiSafe 3 showed a greater charge capacity for solutions with high ionic strength (<3.4), while the scintillator OptiSafe TriSafe no form homogeneous mixtures for solutions of ionic strength higher than 0.3. Counting efficiencies for different proportions of sample and scintillator near 100% for the scintillators OptiSafe HiSafe 3 and Ultima Gold Ab were obtained. In the counting by Cerenkov Effect, the efficiency and sensitivity depended of the vial type; polyethylene vials were more suitable for counting that the glass vials. The sample volume had not significant effect on counting efficiency, obtaining an average value of 44.8% for polyethylene vials and 37.3% for glass vials. Therefore, the liquid scintillation was more efficient and sensitive for the measurement of {sup 40}K in aqueous solutions. (Author)

  20. Simulation of natural radioactivity backgrounds in the central detector

    CERN Document Server

    Li, Xinying; Wen, Liangjian; Li, Weidong; You, Zhengyun; Yu, Chunxu; Zhang, Yumei; Lin, Tao

    2015-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is an experiment proposed to determine the neutrino mass hierarchy and probe the fundamental properties of neutrino oscillation. The JUNO central detector is a spherical liquid scintillator detector with 20 kton fiducial mass. It is required to achieve a $3\\%/\\sqrt{E(MeV)}$ energy resolution with very low radioactive background, which is a big challenge to the detector design. In order to ensure the detector performance can meet the physics requirements, reliable detector simulation is necessary to provide useful information for detector design. A simulation study of natural radioactivity backgrounds in the JUNO central detector has been performed to guide the detector design and set requirements to the radiopurity of detector materials.

  1. Leakage Tests of the Stainless Steel Vessels of the Antineutrino Detectors in the Daya Bay Reactor Neutrino Experiment

    CERN Document Server

    Chen, Xiaohui; Heng, Yuekun; Wang, Lingshu; Tang, Xiao; Ma, Xiaoyan; Zhuang, Honglin; Band, Henry; Cherwinka, Jeff; Xiao, Qiang; Heeger, Karsten M

    2012-01-01

    The antineutrino detectors in the Daya Bay reactor neutrino experiment are liquid scintillator detectors designed to detect low energy particles from antineutrino interactions with high efficiency and low backgrounds. Since the antineutrino detector will be installed in a water Cherenkov cosmic ray veto detector and will run for 3 to 5 years, ensuring water tightness is critical to the successful operation of the antineutrino detectors. We choose a special method to seal the detector. Three leak checking methods have been employed to ensure the seal quality. This paper will describe the sealing method and leak testing results.

  2. Determination of {sup 125}I impurities in [{sup 123}I]labelled radiopharmaceuticals, by liquid scintillation counting: sensitivity of the method

    Energy Technology Data Exchange (ETDEWEB)

    Bonardi, M.L. E-mail: mauro.bonardi@mi.infn.itmauro.bonari@mi.infn.it; Birattari, C.; Groppi, F.; Gini, L.; Mainardi, C.H.S.; Menapace, E

    2004-01-01

    Iodine-125 is a radioisotopic impurity 'always' present in iodine-123, produced by nuclear reactions induced either on natural or 'highly' enriched targets. Liquid scintillation counting is a very sensitive tool to determine low level impurities of both low energy electrons and photons in aqueous and organic solutions of radiopharmaceutical compounds. With this technique it was possible to determine, on commercial samples, that the content of {sup 125}I was of the order of not less than 0.1% for {sup 123}I produced via {sup 127}I(p,5n) reactions and not less than 0.01% for {sup 123}I produced via 'highly' enriched {sup 124}Xe(p,X) nuclear reactions.

  3. Study of the factors affecting the performance of microextraction by packed sorbent (MEPS) using liquid scintillation counter and liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Altun, Zeki [Karlstad University, Faculty of Technology and Science, SE-651 88 Karlstad (Sweden); Abdel-Rehim, Mohamed [Karlstad University, Faculty of Technology and Science, SE-651 88 Karlstad (Sweden); Clinical Pharmacology and DMPK, AstraZeneca R and D Soedertaelje, SE-151 85 Soedertaelje (Sweden)], E-mail: Mohamed.Abdel-Rehim@Astrazeneca.com

    2008-12-23

    Microextraction by packed sorbent (MEPS) is a new technique for sample preparation that can be connected on-line with LC or GC. In MEPS, approximately 1-2 mg of the solid packing material is inserted into a syringe (100-250 {mu}L) as a plug. Sample preparation takes place on the packed bed. The bed can be packed or coated to provide selective and suitable sampling conditions. The new method is very promising for extraction of drugs and metabolites from biological samples. In this paper, some factors affecting the performance of MEPS such as recovery, carry-over, leakage, washing volume and elution volume were studied using C18 and hydroxylated polystyrene-divinylbenzene copolymer (ENV+) as sorbents. Radioactively labelled bupivacaine in plasma samples was used as test analyte. For the extraction of this drug, using methanol/water 95:5 (v/v) (0.25% ammonium hydroxide) was used as elution solvent. The analyte response increased with increasing the elution volume and it was linear upp up to 100 {mu}L utilizing liquid scintillation counter. Further, for concentrating the sample, we found that MEPS may be used such that the sample can be drawn through the needle, up and down, several times. The analyte leakage increases as the volume washing increases, though higher washing volumes may also result in cleaner extracts. To eliminate analyte carry-over, the sorbents were washed first with 3 x 250 {mu}L elution solution and then with 3 x 250 {mu}L washing solution. In addition, the reproducibility measurements show relatively good relative standard deviation (RSD) % values concerning analyte recovery and analyte leakage. The present study provides an understanding of basic aspects when optimizing methods for MEPS. In this study, MEPS was used off-line with liquid scintillation counter and on-line with LC-MS/MS.

  4. Development of a liquid scintillation method for in vitro determination of {sup 226}Ra and {sup 228} Ra in bioassay samples

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Paulo Cesar P.; Sousa, Wanderson O.; Juliao, Ligia M.Q.C.; Dantas, Bernardo M., E-mail: pcesar@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Radium isotopes are dispersed in the environment according to their physicochemical characteristics. The intake of {sup 226}Ra and {sup 228}Ra in humans can occur by inhalation and ingestion and the risk of internal exposure are related to their long half-lives, characteristics of the emission and biokinetics of the isotopes in the human body. The goal of this work is to develop a methodology for the analysis of {sup 226}Ra and {sup 228}Ra in excreta samples (urine and feces), using liquid scintillation technique. Excreta samples were provided by non-exposed humans for the purpose of standardizing the methodology and the establishment of a background level of radium excretion. Radium isotopes were concentrated and separated from the constituents of the sample by co-precipitation with barium sulphate. The precipitate of Ba(Ra)SO{sub 4} was filtrated and weighted for the determination of the chemical yield. The filter containing the precipitate was transferred to a scintillation vial. In the scintillation vial, 8 mL of water, 8 mL of Instagel XF and 4 mL of UltimaGold were added, forming a gel suspension, after stirring the solution. The {sup 226}Ra and {sup 228}Ra activities were determined 21 days after the precipitation of samples. The samples were counted in a liquid scintillation spectrometer. The technique presented adequate sensitivity and reproducibility for the analysis of urine and feces. The activities of {sup 226}Ra and {sup 228}Ra in excreta samples provide useful information for the identification of the main route of intake and for the assessment of the internal exposure of occupationally exposed workers and inhabitants of high background areas. (author)

  5. Magnetic iron oxide nanoparticles for the collection and direct measurement of adsorbed alpha-emitting radionuclides from environmental waters by liquid scintillation analysis

    Energy Technology Data Exchange (ETDEWEB)

    O' Hara, Matthew J.; Addleman, R. Shane

    2017-01-01

    Radioactive contamination in the environment, be it from accidental or intentional release, can create an urgent need to assess water and food supplies, the environment, and monitor human health. Alpha-emitting radionuclides represent the most ionizing, and therefore the most damaging, form of radiation when internalized. Additionally, because of its ease of energy attenuation in solids or liquids, alpha emissions cannot be reliably monitored using non-destructive means. In the event of such an emergency, rapid and efficient methods will be needed to screen scores of samples (food, water, and human excreta) within a short time window. Unfortunately, the assay of alpha-emitting radionuclides using traditional radioanalytical methods is typically labor intensive and time consuming. The creation of analytical counting sources typically requires a series of chemical treatment steps to achieve well performing counting sources. In an effort to devise radioanalytical methods that are fast, require little labor, and minimize the use of toxic or corrosive agents, researchers at PNNL have evaluated magnetite (Fe3O4) nanoparticles as extracting agents for alpha-emitting radionuclides from chemically unmodified aqueous systems. It is demonstrated that bare magnetic nanoparticles exhibit high affinity for representative α-emitting radionuclides (241Am and 210Po) from representative aqueous matrices: river and ground water. Furthermore, use of the magnetic properties of these materials to concentrate the sorbed analyte from the bulk aqueous solution has been demonstrated. The nanoparticle concentrate can be either directly dispensed into scintillation cocktail, or first dissolved and then added to scintillation cocktail as a solution for alpha emission assay by liquid scintillation analysis. Despite the extreme quench caused by the metal oxide suspensions, the authors have demonstrated that quench correction features available on modern liquid scintillation analyzers can be

  6. Using Model-Based Reasoning for Autonomous Instrument Operation - Lessons Learned From IMAGE/LENA

    Science.gov (United States)

    Johnson, Michael A.; Rilee, Michael L.; Truszkowski, Walt; Bailin, Sidney C.

    2001-01-01

    Model-based reasoning has been applied as an autonomous control strategy on the Low Energy Neutral Atom (LENA) instrument currently flying on board the Imager for Magnetosphere-to-Aurora Global Exploration (IMAGE) spacecraft. Explicit models of instrument subsystem responses have been constructed and are used to dynamically adapt the instrument to the spacecraft's environment. These functions are cast as part of a Virtual Principal Investigator (VPI) that autonomously monitors and controls the instrument. In the VPI's current implementation, LENA's command uplink volume has been decreased significantly from its previous volume; typically, no uplinks are required for operations. This work demonstrates that a model-based approach can be used to enhance science instrument effectiveness. The components of LENA are common in space science instrumentation, and lessons learned by modeling this system may be applied to other instruments. Future work involves the extension of these methods to cover more aspects of LENA operation and the generalization to other space science instrumentation.

  7. Interaction of electron neutrino with LSD detector

    Science.gov (United States)

    Ryazhskaya, O. G.; Semenov, S. V.

    2016-06-01

    The interaction of electron neutrino flux, originating in the rotational collapse mechanism on the first stage of Supernova burst, with the LSD detector components, such as 56Fe (a large amount of this metal is included in as shielding material) and liquid scintillator barNnH2n+2, is being investigated. Both charged and neutral channels of neutrino reaction with 12barN and 56Fe are considered. Experimental data, giving the possibility to extract information for nuclear matrix elements calculation are used. The number of signals, produced in LSD by the neutrino pulse of Supernova 1987A is determined. The obtained results are in good agreement with experimental data.

  8. Impact of wind and tides on the Lena River freshwater plume dynamics in the summer season

    Science.gov (United States)

    Fofonova, Vera; Danilov, Sergey; Androsov, Alexey; Janout, Markus; Bauer, Martin; Overduin, Paul; Itkin, Polona; Wiltshire, Karen Helen

    2015-07-01

    The Lena plume dynamics in the Lena Delta region of the Laptev Sea are explored in simulations performed with the Finite Volume Coastal Ocean Model (FVCOM) on a mesh with the horizontal resolution 0.4-5 km. The impact of wind and tides on the Lena plume propagation is analysed based on simulations for the summer season of 2008 and also on idealised experiments. All main Lena River freshwater channels (Trofimovskaya, Bykovskaya, Tumatskaya and Olenekskaya) produce buoyant outflows in the summer season. The surface plume buoyancy signature proves to be highly variable in time, especially in case of upwelling favourable wind events. Winds stronger than 6 m s-1 can already turn the dynamics of flows from all main freshwater channels to the wind-driven state. During the summer season, the bulk of freshwater from the Lena River stays in the eastern Laptev Sea because of location of the main Lena River freshwater channels, their large Kelvin numbers and light summer winds. Westward and northward plume excursions are wind-driven, and the model skill in simulating them depends on the available wind forcing. The main mechanism of tidal influence in the freshwater plume zone is through tidally induced mixing, except for the northern vicinity of the delta, where residual circulation may contribute to the plume eastward transport significantly.

  9. The development of gaseous detectors with solid photocathodes for low temperature applications

    CERN Document Server

    Periale, L.; Iacobaeus, C.; Francke, T.; Lund-Jensen, B.; Pavlopoulos, N.; Picchi, P.; Pietropaolo, F.

    2004-01-01

    There are several applications and fundamental research areas which require the detection of VUV light at cryogenic temperatures. For these applications we have developed and successfully tested special designs of gaseous detectors with solid photocathodes able to operate at low temperatures: sealed gaseous detectors with MgF2 windows and windowless detectors. We have experimentally demonstrated, that both primary and secondary (due to the avalanche multiplication inside liquids) scintillation lights could be recorded by photosensitive gaseous detectors. The results of this work may allow one to significantly improve the operation of some noble liquid gas TPCs.

  10. Measurement of Neutron and Muon Fluxes 100~m Underground with the SciBath Detector

    Energy Technology Data Exchange (ETDEWEB)

    Garrison, Lance [Indiana Univ., Bloomington, IN (United States)

    2014-01-01

    The SciBath detector is an 80 liter liquid scintillator detector read out by a three dimensional grid of 768 wavelength-shifting fibers. Initially conceived as a fine-grained charged particle detector for neutrino studies that could image charged particle tracks in all directions, it is also sensitive to fast neutrons (15-200 MeV). In fall of 2011 the apparatus performed a three month run to measure cosmic-induced muons and neutrons 100~meters underground in the FNAL MINOS near-detector area. Data from this run has been analyzed and resulted in measurements of the cosmic muon flux as \

  11. The LUX-Zeplin Dark Matter Detector

    Science.gov (United States)

    Mock, Jeremy; Lux-Zeplin (Lz) Collaboration

    2016-03-01

    The LUX-ZEPLIN (LZ) detector is a second generation dark matter experiment that will operate at the 4850 foot level of the Sanford Underground Research Experiment as a follow-up to the LUX detector, currently the world's most sensitive WIMP direct detection experiment. The LZ detector will contain 7 tonnes of active liquid xenon with a 5.6 tonne fiducial mass in the TPC. The TPC is surrounded by an active, instrumented, liquid-xenon ``skin'' region to veto gammas, then a layer of liquid scintillator to veto neutrons, all contained within a water shield. Modeling the detector is key to understanding the expected background, which in turn leads to a better understanding of the projected sensitivity, currently expected to be 2e-48 cm2 for a 50 GeV WIMP. I will discuss the current status of the LZ experiment as well as its projected sensitivity.

  12. Preparation of manganese salts of carboxylic acids labelled with ''54Mn and comparison with ''54 MnCl{sub 2} in liquid scintillation counting; Preparacion de sales manganosas de acidos alifaticos monocarboxilicos marcados con ''54 MnCl{sub 2} en medidas por centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Arcos Merino, J. M. los; Grau Malonda, A.

    1992-07-01

    Procedures for liquid scintillation sample preparation of manganese dimethylbutirate, decanoate and palmitate, labelled with 54 Mn are described. their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene. HISafe II. PCS, instagel. Dioxane-naphtalene and Toluene-alcohol. For comparison, Inorganic 54 MnCl-2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (Author)

  13. Analytical method of Kr-85 determination, using cryogenic concentration and separation and liquid scintillation counting; Desarrollo del metodo de concentracion y se paracion criogenica cromatografica y medida radiactiva por centelleo liquido de Kr-85

    Energy Technology Data Exchange (ETDEWEB)

    Heras, M. C.; Perez, M. M.; Grau, A.

    1983-07-01

    The method used in the Laboratory of the JEN for the determination of Kr-85 levels in gaseous effluents of nuclear power and in the atmosphere is described. Samples of air, collected in metallic cylinders, are introduced into a gas-solid chromatographic separation system which resolves Kr from the other air components. The separated Kr ia dissolved in a toluene based scintillation cocktail, and the Kr-85 content is determined by liquid scintillation counting. (Author)

  14. Influence of atomic and nuclear constants on the counting efficiency for 55{sup F}e in liquid scintillators; Influencia de los parametros atomicos y nucleares en la calibracion de 55{sup F}e mediante centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A.; Grau, A.; Arcos, J. M. los

    1985-07-01

    In this paper one considers the influence of the different parameters on the determination of the uncertainty of the detection efficiency for 55{sup F}e when the counting technique of liquid scintillation is applied. The following parameters are considered: the relative probabilities of X and Auger emission so as their corresponding energies, the fluorescence yields W{sup K} and W{sup L}, and the non-interaction probabilities of the emitted X photons. (Author) 11 refs.

  15. Determination of Carbon-14 in environmental samples by mixing 14CO{sub 2} with a liquid scintillator; Determinacion de carbono-14 en muestras ambientales por incorporacion de 14CO{sub 2} a un centelleador liquido

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. R.; Gomez, V.; Heras, M. C.; Beltran, M. A.

    1990-07-01

    A method for the determination of Carbon-14 (14CO2) in environmental samples has been developed. The method use the direct absorption of the carbon dioxide into Carbosorb, followed with incorporation of the mixture (Carbosorb-CO2) to the liquid scintillator. The results obtained to apply this method and the benzene synthesis, usual in our laboratory, are discussed and compared. The method of collection of atmospheric samples is also described. (Author) 10 refs.

  16. Liquid Scintillation Counting Standardization of {sup 2}2NaCl by te CIEMAT/NIST method; Calibracion por Centelleo Liquido del ''22NaCl, mediante el metodo CIEMAT/NIST

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Grau Carles, A.; Grau Malonda, A.

    1995-07-01

    We describe a procedure for preparing a stable solution of ''22NaCl for liquid scintillation counting and its counting stability and spectral evolution in Insta-Gel''R is studied. The solution has been standardised in terms of activity concentration by the CIEMAT/NIST method with discrepancies between experimental and computed efficiencies lower than 0.4 % and an overall uncertainty of 0.35 %. (Author) 4 refs.

  17. Measurement by liquid scintillation of {sup 226} Ra coprecipitated in BaSO{sub 4}; Medicion por centelleo liquido de {sup 226} Ra coprecipitado en BaSO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Rio, H.; Davila R, J.I.; Badillo A, V.E.; Mireles G, F.; Quirino T, L.; Lugo R, J.F.; Pinedo V, J.L.; Rios M, C. [UAEN-UAZ, A.P. 579C, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)]. e-mail: idavila@cantera.reduaz.mx

    2003-07-01

    The {sup 226} Ra is one of the more radio toxic nuclides since when entering to the organism it continues metabolically to the calcium, accumulating mainly in the bone tissue where it becomes in an internal radiation source. For the analysis of radium in water the methods of radon emanation are generally applied and coprecipitation with barium sulfate. This last is quick and efficient, and the radium in the precipitate can be measured by alpha or gamma spectrometry, or liquid scintillation dissolving the precipitate one with EDTA. In this work it is proposed a procedure for the radium measurement in water based on the coprecipitation with barium sulfate and in the detection by liquid scintillation. The precipitate of Ba(Ra)SO{sub 4} it is carried with water and blended with the liquid scintillator OptiPhase Hi Safe 3, avoiding the dissolution with EDTA. A 92{+-} 1.4% of radium it was recovered and it was reached a minimum activity detectable of 4.2 {+-} 0.9 mBq{sup -1}. The procedure was essayed with natural mineral water with a knew activity in concentration of {sup 226} Ra. The analytic result it coincided with the reported value with a relative error of 9%. (Author)

  18. Performance of two liquids scintillation and optimization of a Wallac 1411 counter in the tritium quantification in aqueous samples; Desempeno de dos centelleadores liquidos y optimizacion de un contador Wallac 1411 en la cuantificacion de tritio en muestras acuosas

    Energy Technology Data Exchange (ETDEWEB)

    Contreras de la Cruz, E. de J.; Lopez del Rio, H.; Davila R, J. I.; Mireles G, F.; Pinedo V, J. L., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The optimization of a liquid scintillation counting Wallac 1411 is presented as well as the performance of the liquids scintillation miscible in water OptiPhase Hi Safe 3 and Last Gold Ab, in the tritium quantification in aqueous samples. The luminescence effect, the quenching, the solution ph and the level of pulse amplitude comparator (Pac) were evaluated in the response of both liquids scintillation in the tritium measurement. The quenching and the luminescence modify the scintillators response; in the first of them the counting efficiency decreases and the minimum detectable activity increases; the second interferes in the tritium quantification in the interest window, but the effect disappears after 4 hours of darkness of the samples. The maximum counting efficiency was of 24% for OptiPhase Hi Safe 3 and 31% for Last Gold Ab, diminishing with the quenching until values of 8 and 11%, respectively. For a counting time of 6 hours and lower quenching, the minimum detectable concentration for OptiPhase Hi Safe 3 was of 13.4 ± 0.2 Bq/L and 9.9 ± 0.1 Bq/L for Last Gold Ab. Both scintillators responded appropriately to sour and basic solutions, being only presented chemiluminescence in Last Gold Ab to ph highly basic. The Pac application that varies between 1 and 256 does not have effect in the tritium measurement until values above 90. (Author)

  19. Distribution of methane in the Lena Delta and Buor Khaya Bay, Russia

    Directory of Open Access Journals (Sweden)

    I. Bussmann

    2012-11-01

    Full Text Available The Lena River is one of the largest Russian rivers draining into the Laptev Sea. The permafrost areas surrounding the Lena are predicted to melt at increasing rates due to global temperature increases. With this melting, large amounts of carbon – either organic or as methane – will reach the waters of the Lena and the adjacent Buor Khaya Bay (Laptev Sea.

    Methane concentrations and the isotopic signal of methane in the waters of the Lena Delta and estuary were monitored from 2008 to 2010. Meltwater run-off of permafrost soils produced hotspots for methane input into the river system (median concentration 1500 nM compared with concentrations of around 100 nM observed in the main channels of the Lena. Within the river, especially at sites with meltwater input, microbiological experiments indicated strong in situ methane production but a very low methane oxidation potential. In the estuary of Buor Khaya Bay, methane concentrations decreased towards background levels of 20 nM. Here, the strong stratification of the water column permits the dilution of methane with seawater, and methane is released mainly by diffusion into the atmosphere.

  20. Effective determination of the long-lived nuclide 41Ca in nuclear reactor bioshield concretes: comparison of liquid scintillation counting and accelerator mass spectrometry.

    Science.gov (United States)

    Warwick, P E; Croudace, I W; Hillegonds, D J

    2009-03-01

    The routine application of liquid scintillation counting to (41)Ca determination has been hindered by the absence of traceable calibration standards of known (41)Ca activity concentrations. The introduction of the new IRMM (41)Ca mass-spectrometric standards with sufficiently high (41)Ca activities for radiometric detection has partly overcome this although accurate measurement of stable Ca concentrations coupled with precise half-life data are still required to correct the certified (41)Ca:(40)Ca ratios to (41)Ca activity concentrations. In this study, (41)Ca efficiency versus quench curves have been produced using the IRMM standard, and their accuracy validated by comparison with theoretical calculations of (41)Ca efficiencies. Further verification of the technique was achieved through the analysis of (41)Ca in a reactor bioshield core that had been previously investigated for other radionuclide variations. Calcium-41 activity concentrations of up to 25 Bq/g were detected. Accelerator mass spectrometry (AMS) measurements of the same suite of samples showed a very good agreement, providing validation of the procedure. Calcium-41 activity concentrations declined exponentially with distance from the core of the nuclear reactor and correlated well with the predicted neutron flux.

  1. Determination of {sup 55}Fe in waste waters of the Krsko nuclear power plant measured simultaneously by liquid scintillation spectrometer (LSC) and X-ray spectrometer (XRS)

    Energy Technology Data Exchange (ETDEWEB)

    Mikelic, L. [Rudjer Boskovic Institute, Laboratory for Radioecology, Bijenicka Cesta 54, 10000 Zagreb (Croatia)], E-mail: lmikelic@irb.hr; Orescanin, V.; Lulic, S. [Rudjer Boskovic Institute, Laboratory for Radioecology, Bijenicka Cesta 54, 10000 Zagreb (Croatia)

    2007-10-15

    This paper presents comparison of two methods for the determination of {sup 55}Fe activity of waste waters discharged from the Krsko nuclear power plant (KNPP). Research was conducted on 12 composite samples of waste water collected in the waste monitor tank (WMT) during each month as well as on Analytics, Inc. cross-check sample. Results showed that the complicated and time-consuming method proposed by the Environmental Measurements Laboratory (EML) could be successfully replaced with a simple and fast based on the extraction of {sup 55}Fe from waste water by non-specific chelating agent ammonium-pyrrolidinedithiocarbamate (APDC) at pH 4 after separation from cobalt, and activity measurement by X-ray fluorescence spectroscopy (XRS). Results obtained by the XRS method were approximately 8.6% lower than those obtained by liquid scintillation spectrometer (LSC). The mean deviation of the XRS results from the activity of cross-check sample was 2.47%, which ensures that this method is accurate enough for environmental monitoring.

  2. Determination of 55Fe in waste waters of the Krsko nuclear power plant measured simultaneously by liquid scintillation spectrometer (LSC) and X-ray spectrometer (XRS)

    Science.gov (United States)

    Mikelic, L.; Orescanin, V.; Lulic, S.

    2007-10-01

    This paper presents comparison of two methods for the determination of 55Fe activity of waste waters discharged from the Krsko nuclear power plant (KNPP). Research was conducted on 12 composite samples of waste water collected in the waste monitor tank (WMT) during each month as well as on Analytics, Inc. cross-check sample. Results showed that the complicated and time-consuming method proposed by the Environmental Measurements Laboratory (EML) could be successfully replaced with a simple and fast based on the extraction of 55Fe from waste water by non-specific chelating agent ammonium-pyrrolidinedithiocarbamate (APDC) at pH 4 after separation from cobalt, and activity measurement by X-ray fluorescence spectroscopy (XRS). Results obtained by the XRS method were approximately 8.6% lower than those obtained by liquid scintillation spectrometer (LSC). The mean deviation of the XRS results from the activity of cross-check sample was 2.47%, which ensures that this method is accurate enough for environmental monitoring.

  3. Development of liquid scintillation based 4πβ(LS)-γ coincidence counting system and demonstration of its performance by standardization of ⁶⁰Co.

    Science.gov (United States)

    Kulkarni, D B; Anuradha, R; Joseph, Leena; Tomar, B S

    2013-02-01

    A single-vial, single-PMT 4πβ(LS)-γ coincidence counting system has been developed at the Radiation Safety Systems Division, BARC. It has advantages of simple sample preparation, higher counting efficiency and the absence of self absorption over the conventional proportional counter based 4πβ(PC)-γ coincidence counting system. The performance of the system is demonstrated by standardizing a (60)Co solution using the 4πβ(LS)-γ coincidence counting system, 4πβ(PC)-γ coincidence counting system and CIEMAT/NIST method and comparing the results obtained by each method. The detection efficiency of liquid scintillation counter of the 4πβ(LS)-γ coincidence counting system was varied by color quenching, by chemical quenching and by varying the bias voltage applied to the LSC PMT. For the proportional counter based 4πβ(PC)-γ coincidence counting system the detection efficiency was varied by source self absorption. The activity concentrations obtained using the 4πβ(LS)-γ coincidence counting system, the 4πβ(PC)-γ coincidence counting system and the CIEMAT/NIST method are comparable within the uncertainty limits.

  4. Survey on the presence of 90Sr in milk samples by a validated ultra low level liquid scintillation counting (LSC method

    Directory of Open Access Journals (Sweden)

    dell’Oro D.

    2013-04-01

    Full Text Available 90Sr is one of the most biologically hazardous radionuclides produced in nuclear fission processes and decays emitting high-energy beta particles turning 90Y. 90Sr is transferred from soil-plant to cow’s milk and then to humans if it is introduced into the environment. Radiostrontium is chemically similar to calcium entering the human body through several food chains and depositing in bone and blood-forming tissue (bone marrow. Among main foodstuffs assumed in human diet, milk is considered of special interest for radiostrontium determination, especially in emergency situations, because the consumption of contaminated milk is the main source of internal radiation exposure, particularly for infants. In this work an analytical method for the determination of radiostrontium in milk was developed and validated in order to determine low activity levels by liquid scintillation counting (LSC after achieving 90Y secular equilibrium condition. The analytical procedure was applied both in surveillance and routine programmes to detect radiocontamination in cow’s, goat and sheep milk samples.

  5. Prospects of the search for neutrino bursts from Supernovae with Baksan Large Volume Scintillation Detector

    CERN Document Server

    Petkov, V B

    2015-01-01

    Observing a high-statistics neutrino signal from the supernova explosions in the Galaxy is a major goal of low-energy neutrino astronomy. The prospects for detecting all flavors of neutrinos and antineutrinos from the core-collapse supernova (ccSN) in operating and forthcoming large liquid scintillation detectors (LLSD) are widely discussed now. One of proposed LLSD is Baksan Large Volume Scintillation Detector (BLVSD). This detector will be installed at the Baksan Neutrino Observatory (BNO) of the Institute for Nuclear Research, Russian Academy of Sciences, at a depth of 4800 m.w.e. Low-energy neutrino astronomy is one of the main lines of research of the BLVSD.

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

    CERN Document Server

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

    2002-01-01

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

  7. A compact ultra-clean system for deploying radioactive sources inside the KamLAND detector

    Energy Technology Data Exchange (ETDEWEB)

    Banks, T.I., E-mail: tbanks@berkeley.edu [Physics Department, University of California, Berkeley, CA 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Freedman, S.J. [Physics Department, University of California, Berkeley, CA 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Wallig, J.; Ybarrolaza, N. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gando, A.; Gando, Y.; Ikeda, H. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Inoue, K. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Kishimoto, Y. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Koga, M. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Mitsui, T. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Nakamura, K. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Shimizu, I.; Shirai, J.; Suzuki, A.; Takemoto, Y.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B.D. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); and others

    2015-01-01

    We describe a compact, ultra-clean device used to deploy radioactive sources along the vertical axis of the KamLAND liquid-scintillator neutrino detector for purposes of calibration. The device worked by paying out and reeling in precise lengths of a hanging, small-gauge wire rope (cable); an assortment of interchangeable radioactive sources could be attached to a weight at the end of the cable. All components exposed to the radiopure liquid scintillator were made of chemically compatible UHV-cleaned materials, primarily stainless steel, in order to avoid contaminating or degrading the scintillator. To prevent radon intrusion, the apparatus was enclosed in a hermetically sealed housing inside a glove box, and both volumes were regularly flushed with purified nitrogen gas. An infrared camera attached to the side of the housing permitted real-time visual monitoring of the cable's motion, and the system was controlled via a graphical user interface.

  8. A compact ultra-clean system for deploying radioactive sources inside the KamLAND detector

    CERN Document Server

    Banks, T I; Wallig, J; Ybarrolaza, N; Gando, A; Gando, Y; Ikeda, H; Inoue, K; Kishimoto, Y; Koga, M; Mitsui, T; Nakamura, K; Shimizu, I; Shirai, J; Suzuki, A; Takemoto, Y; Tamae, K; Ueshima, K; Watanabe, H; Xu, B D; Yoshida, H; Yoshida, S; Kozlov, A; Grant, C; Keefer, G; Piepke, A; Bloxham, T; Fujikawa, B K; Han, K; Ichimura, K; Murayama, H; O'Donnell, T; Steiner, H M; Winslow, L A; Dwyer, D A; McKeown, R D; Zhang, C; Berger, B E; Lane, C E; Maricic, J; Miletic, T; Batygov, M; Learned, J G; Matsuno, S; Sakai, M; Horton-Smith, G A; Downum, K E; Gratta, G; Efremenko, Y; Perevozchikov, O; Karwowski, H J; Markoff, D M; Tornow, W; Heeger, K M; Detwiler, J A; Enomoto, S; Decowski, M P

    2014-01-01

    We describe a compact, ultra-clean device used to deploy radioactive sources along the vertical axis of the KamLAND liquid-scintillator neutrino detector for purposes of calibration. The device worked by paying out and reeling in precise lengths of a hanging, small-gauge wire rope (cable); an assortment of interchangeable radioactive sources could be attached to a weight at the end of the cable. All components exposed to the radiopure liquid scintillator were made of chemically compatible UHV-cleaned materials, primarily stainless steel, in order to avoid contaminating or degrading the scintillator. To prevent radon intrusion, the apparatus was enclosed in a hermetically sealed housing inside a glove box, and both volumes were regularly flushed with purified nitrogen gas. An infrared camera attached to the side of the housing permitted real-time visual monitoring of the cable's motion, and the system was controlled via a graphical user interface.

  9. Comparison of Fast Neutron Detector Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Stange, Sy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mckigney, Edward Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-09

    This report documents the work performed for the Department of Homeland Security Domestic Nuclear Detection O ce as the project Fast Neutron Detection Evaluation under contract HSHQDC-14-X-00022. This study was performed as a follow-on to the project Study of Fast Neutron Signatures and Measurement Techniques for SNM Detection - DNDO CFP11-100 STA-01. That work compared various detector technologies in a portal monitor con guration, focusing on a comparison between a number of fast neutron detection techniques and two standard thermal neutron detection technologies. The conclusions of the earlier work are contained in the report Comparison of Fast Neutron Detector Technologies. This work is designed to address questions raised about assumptions underlying the models built for the earlier project. To that end, liquid scintillators of two di erent sizes{ one a commercial, o -the-shelf (COTS) model of standard dimensions and the other a large, planer module{were characterized at Los Alamos National Laboratory. The results of those measurements were combined with the results of the earlier models to gain a more complete picture of the performance of liquid scintillator as a portal monitor technology.

  10. Study of n-{\\gamma} discrimination in low energy range (above 40 keVee) by charge comparison method with a BC501A liquid scintillation detector

    CERN Document Server

    Chen, Yonghao; Zhang, Xiaodong; Lei, Jiarong; An, Li; Shao, Jianxiong; Zheng, Pu; Wang, Xinhua; Zhu, Chuanxin; He, Tie; Yang, Jian

    2013-01-01

    A VME-based experiment system for n-{\\gamma} discrimination using the charge comparison method was established. A data acquisition program for controlling the programmable modules and processing data online via VME64X bus was developed through the use of LabVIEW. The two-dimensional (2D) scatter plots of the charge in the slow component vs. the total charge of recorded pulses from Am-Be and Cf neutron sources were presented. The 2D scatter plots of the energy vs. the ratio of the charge in the slow component to the total charge of the pulses were presented at the meantime. The quality of n-{\\gamma} discrimination was checked by the figure-of-merit, and the results showed good performance of n-{\\gamma} discrimination at low energy range. Neutrons and {\\gamma}-rays were separated above 50 keVee (electron-equivalent energy). The quality of n-{\\gamma} discrimination have been improved compared with others' results at 5 energies (150, 250, 350, 450, 550 keVee).

  11. Microfluidic Scintillation Detectors for High Energy Physics

    CERN Document Server

    Maoddi, Pietro; Mapelli, Alessandro

    This thesis deals with the development and study of microfluidic scintillation detectors, a technology of recent introduction for the detection of high energy particles. Most of the interest for such devices comes from the use of a liquid scintillator, which entails the possibility of changing the active material in the detector, leading to increased radiation resistance. A first part of the thesis focuses on the work performed in terms of design and modelling studies of novel prototype devices, hinting to new possibilities and applications. In this framework, the simulations performed to validate selected designs and the main technological choices made in view of their fabrication are addressed. The second part of this thesis deals with the microfabrication of several prototype devices. Two different materials were studied for the manufacturing of microfluidic scintillation detectors, namely the SU-8 photosensitive epoxy and monocrystalline silicon. For what concerns the former, an original fabrication appro...

  12. Fast-neutron induced background in LaBr{sub 3}:Ce detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kiener, J., E-mail: Jurgen.Kiener@csnsm.in2p3.fr [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), CNRS-IN2P3 et Université Paris-Sud, 91405 Campus Orsay (France); Tatischeff, V.; Deloncle, I. [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), CNRS-IN2P3 et Université Paris-Sud, 91405 Campus Orsay (France); Séréville, N. de [Institut de Physique Nucléaire d' Orsay, CNRS-IN2P3 and Université Paris-Sud, 91406 Orsay (France); Laurent, P. [CEA/IRFU Service d' Astrophysique, Orme des Merisiers, CEA Saclay, 91191 Gif-sur-Yvette (France); Laboratoire Astroparticules et Cosmologie (APC), 10, rue A. Domon et L. Duquet, 75205 Paris (France); Blondel, C. [Laboratoire AIM, CEA/IRFU, Orme des Merisiers, CEA Saclay, 91191 Gif-sur-Yvette (France); Chabot, M. [Institut de Physique Nucléaire d' Orsay, CNRS-IN2P3 and Université Paris-Sud, 91406 Orsay (France); Chipaux, R. [CEA/DMS/IRFU/SEDI, CEA Saclay, 91191 Gif sur Yvette (France); Coc, A. [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), CNRS-IN2P3 et Université Paris-Sud, 91405 Campus Orsay (France); Dubos, S. [Laboratoire AIM, CEA/IRFU, Orme des Merisiers, CEA Saclay, 91191 Gif-sur-Yvette (France); Gostojic, A. [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), CNRS-IN2P3 et Université Paris-Sud, 91405 Campus Orsay (France); and others

    2015-10-21

    The response of a scintillation detector with a cylindrical 1.5-in. LaBr{sub 3}:Ce crystal to incident neutrons has been measured in the energy range E{sub n} = 2–12 MeV. Neutrons were produced by proton irradiation of a Li target at E{sub p} = 5–14.6 MeV with pulsed proton beams. Using the time-of-flight information between target and detector, energy spectra of the LaBr{sub 3}:Ce detector resulting from fast neutron interactions have been obtained at 4 different neutron energies. Neutron-induced γ rays emitted by the LaBr{sub 3}:Ce crystal were also measured in a nearby Ge detector at the lowest proton beam energy. In addition, we obtained data for neutron irradiation of a large-volume high-purity Ge detector and of a NE-213 liquid scintillator detector, both serving as monitor detectors in the experiment. Monte-Carlo type simulations for neutron interactions in the liquid scintillator, the Ge and LaBr{sub 3}:Ce crystals have been performed and compared with measured data. Good agreement being obtained with the data, we present the results of simulations to predict the response of LaBr{sub 3}:Ce detectors for a range of crystal sizes to neutron irradiation in the energy range E{sub n} = 0.5–10 MeV.

  13. Intial performance from the NOvA surface prototype detector

    Energy Technology Data Exchange (ETDEWEB)

    Muether, M.; /Fermilab

    2011-09-01

    NOvA, the NuMI Off-Axis {nu}{sub e} Appearance experiment, will study {nu}{sub {mu}} {yields} {nu}{sub e} oscillations characterized by the mixing angle {Theta}{sub 13}. Provided {Theta}{sub 13} is large enough, NOvA may ultimately determine the ordering of the neutrino masses and measure CP violation in neutrino oscillations. A complementary pair of detectors will be constructed {approx}14 mrad off beam axis to optimize the energy profile of the neutrinos. This system consists of a surface based 14 kTon liquid scintillator tracking volume located 810 km from the main injector source (NuMI) in Ash River, Minnesota and a smaller underground 222 Ton near detector at the Fermilab. The first neutrino signals at the Ash River Site are expected prior to the 2012 accelerator shutdown. In the meantime, a near detector surface prototype has been completed and neutrinos from two Fermilab sources have been observed using the same highly segmented PVC and liquid scintillator detector system that will be deployed in the full scale experiment. Design and initial performance characteristics of this prototype system are being fed back into the design for the full NOvA program.

  14. Results from the Puebla extensive air shower detector array

    Science.gov (United States)

    Salazar, H.; Martinez, O.; Moreno, E.; Cotzomi, J.; Villaseñor, L.; Saavedrac, O.

    2003-07-01

    We describe the design and operation of the first stage of the EAS-UAP extensive air shower array, as a detector of very high energy cosmic rays ( Eo > 10 14eV). The array is located at the Campus of Puebla University and consists of 18 liquid scintillator detectors, with an active surface of 1 m2 each and a detector spacing of 20 m in a square grid. In this report we discuss the stability and the calibration of the detector array, as derived from the 10 detectors in operation in the first stage. The main characteristics of the array allow us also to use it as an educational and training facility. First distributions of the arrival direction and the lateral shower srpead are also given.

  15. A new value for the half-life of {sup 10}Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting

    Energy Technology Data Exchange (ETDEWEB)

    Korschinek, G., E-mail: Gunther.Korschinek@ph.tum.d [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Bergmaier, A. [Universitaet der Bundeswehr Muenchen, Fakultaet fuer Luft- und Raumfahrttechnik, Institut fuer Angewandte Physik und Messtechnik LRT2, Werner-Heisenberg-Weg 39, D-85577 Neubiberg (Germany); Faestermann, T. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Gerstmann, U.C. [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstaedter Landstr. 1, D-85764 Neuherberg (Germany); Knie, K.; Rugel, G. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Wallner, A. [VERA Laboratory, Faculty of Physics, University of Vienna, Waehringer Strasse 17, A-1090 Wien (Austria); Dillmann, I. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Dollinger, G. [Universitaet der Bundeswehr Muenchen, Fakultaet fuer Luft- und Raumfahrttechnik, Institut fuer Angewandte Physik und Messtechnik LRT2, Werner-Heisenberg-Weg 39, D-85577 Neubiberg (Germany); Lierse von Gostomski, Ch. [Lehrstuhl fuer Radiochemie, Technische Universitaet Muenchen, D-85748 Garching (Germany); Kossert, K. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Maiti, M.; Poutivtsev, M. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Remmert, A. [Lehrstuhl fuer Radiochemie, Technische Universitaet Muenchen, D-85748 Garching (Germany)

    2010-01-15

    The importance of {sup 10}Be in different applications of accelerator mass spectrometry (AMS) is well-known. In this context the half-life of {sup 10}Be has a crucial impact, and an accurate and precise determination of the half-life is a prerequisite for many of the applications of {sup 10}Be in cosmic-ray and earth science research. Recently, the value of the {sup 10}Be half-life has been the centre of much debate. In order to overcome uncertainties inherent in previous determinations, we introduced a new method of high accuracy and precision. An aliquot of our highly enriched {sup 10}Be master solution was serially diluted with increasing well-known masses of {sup 9}Be. We then determined the initial {sup 10}Be concentration by least square fit to the series of measurements of the resultant {sup 10}Be/{sup 9}Be ratio. In order to minimize uncertainties because of mass bias which plague other low-energy mass spectrometric methods, we used for the first time Heavy-Ion Elastic Recoil Detection (HI-ERD) for the determination of the {sup 10}Be/{sup 9}Be isotopic ratios, a technique which does not suffer from difficult to control mass fractionation. The specific activity of the master solution was measured by means of accurate liquid scintillation counting (LSC). The resultant combination of the {sup 10}Be concentration and activity yields a {sup 10}Be half-life of T{sub 1/2} = 1.388 +- 0.018 (1 s, 1.30%) Ma. In a parallel but independent study (Chmeleff et al. ), found a value of 1.386 +- 0.016 (1.15%) Ma. Our recommended weighted mean and mean standard error for the new value for {sup 10}Be half-life based on these two independent measurements is 1.387 +- 0.012 (0.87%) Ma.

  16. Light output of EJ228 scintillation neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Stevanato, L., E-mail: luca.stevanato@pd.infn.i [Dipartimento di Fisica dell' Universita di Padova, Via Marzolo 8, I-35131 Padova (Italy); Fabris, D. [INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Hao, Xin [Dipartimento di Fisica dell' Universita di Padova, Via Marzolo 8, I-35131 Padova (Italy); Lunardon, M.; Moretto, S. [Dipartimento di Fisica dell' Universita di Padova, Via Marzolo 8, I-35131 Padova (Italy); INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Nebbia, G.; Pesente, S. [INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Sajo-Bohus, L. [Universidad Simon-Bolivar, Laboratorio Fisica Nuclear, Apartado 8900, 1080 A. Caracas (Venezuela, Bolivarian Republic of); Viesti, G. [Dipartimento di Fisica dell' Universita di Padova, Via Marzolo 8, I-35131 Padova (Italy); INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy)

    2011-02-15

    The light output of neutron detectors based on the plastic scintillator EJ228 is studied as a function of neutron energy using a time tagged {sup 252}Cf source. Calibration of the light output scale is performed by fitting the experimental distribution of Compton scattering events of photons from a {sup 22}Na source with a response function obtained by Gaussian smearing of the predicted line-shape. The light output curve as well as the pulse height resolution for the EJ228 scintillators is very close (within 5%) to those recently reported for NE213 type organic liquid scintillators.

  17. An Exploratory Study of "Quantitative Linguistic Feedback": Effect of LENA Feedback on Adult Language Production

    Science.gov (United States)

    Suskind, Dana; Leffel, Kristin R.; Hernandez, Marc W.; Sapolich, Shannon G.; Suskind, Elizabeth; Kirkham, Erin; Meehan, Patrick

    2013-01-01

    A child's early language environment is critical to his or her life-course trajectory. Quantitative linguistic feedback utilizes the Language ENvironment Analysis (LENA) technology as a tool to analyze verbal interactions and reinforce behavior change. This exploratory pilot study evaluates the feasibility and efficacy of a novel behavior-change…

  18. Fast-neutron induced background in LaBr3:Ce detectors

    CERN Document Server

    Kiener, J; Deloncle, I; de Séréville, N; Laurent, P; Blondel, C; Chabot, M; Chipaux, R; Coc, A; Dubos, S; Gostojic, A; Goutev, N; Hamadache, C; Hammache, F; Horeau, B; Limousin, O; Ouichaoui, S; Prévot, G; Rodríguez-Gasén, R; Yavahchova, M S

    2015-01-01

    The response of a scintillation detector with a cylindrical 1.5-inch LaBr3:Ce crystal to incident neutrons has been measured in the energy range En = 2-12 MeV. Neutrons were produced by proton irradiation of a Li target at Ep = 5-14.6 MeV with pulsed proton beams. Using the time-of-flight information between target and detector, energy spectra of the LaBr3:Ce detector resulting from fast neutron interactions have been obtained at 4 different neutron energies. Neutron-induced gamma rays emitted by the LaBr3:Ce crystal were also measured in a nearby Ge detector at the lowest proton beam energy. In addition, we obtained data for neutron irradiation of a large-volume high-purity Ge detector and of a NE-213 liquid scintillator detector, both serving as monitor detectors in the experiment. Monte-Carlo type simulations for neutron interactions in the liquid scintillator, the Ge and LaBr3:Ce crystals have been performed and compared with measured data. Good agreement being obtained with the data, we present the resul...

  19. Phytoplankton community structure in the Lena Delta (Siberia, Russia) in relation to hydrography

    Science.gov (United States)

    Kraberg, A. C.; Druzhkova, E.; Heim, B.; Loeder, M. J. G.; Wiltshire, K. H.

    2013-02-01

    The Lena Delta in Northern Siberia is one of the largest river deltas in the world. During peak discharge, after the ice melt in spring, it delivers between 60-8000 m3s-1 of water and sediment into the Arctic Ocean. The Lena Delta and the Laptev Sea coast also constitute a~continuous permafrost region. Ongoing climate change, which is particularly pronounced in the Arctic, is leading to increased rates of permafrost thaw. This is likely to profoundly change the discharge rates of the Lena River and the chemistry of the river waters which are discharged into the coastal Laptev Sea, e.g. by increasing concentrations of inorganic nutrients, DOC and importantly methane. These physical and chemical changes will also affect the composition of and interactions between phytoplankton and zooplankton communities, forming the basis of the food web. However, before potential consequences of climate change for coastal arctic plankton communities can be judged, the inherent status of the diversity and linked foodweb interactions within the delta need to be established. As part of the AWI Lena Delta Programme in 2010 the phyto- and microzooplankton community in three river channels as well as four coastal transects were investigated to capture the typical river phytoplankton communities and the transitional zone of brackish/marine conditions. Most CTD profiles from 23 coastal stations showed very strong stratification. The only exception to this was a small a shallow and mixed area running from the outflow of Bykovskaya channel in a northerly direction parallel to the shore (transect 3). Of the five stations in this area three had a salinity of close to zero. Two further stations had salinities of around 2 and 5 throughout the water column. In the remaining transects on the other hand salinities varied between 5-30 with depth. Phytoplankton counts from the outflow from the Lena were dominated by diatoms (Aulacoseira species) cyanobacteria (Aphanizomenon, Pseudanabaena) and

  20. Integrated hydrological and water quality model for river management: A case study on Lena River

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, André, E-mail: andrerd@gmail.com; Botelho, Cidália; Boaventura, Rui A.R.; Vilar, Vítor J.P., E-mail: vilar@fe.up.pt

    2014-07-01

    The Hydrologic Simulation Program FORTRAN (HSPF) model was used to assess the impact of wastewater discharges on the water quality of a Lis River tributary (Lena River), a 176 km{sup 2} watershed in Leiria region, Portugal. The model parameters obtained in this study, could potentially serve as reference values for the calibration of other watersheds in the area or with similar climatic characteristics, which don't have enough data for calibration. Water quality constituents modeled in this study included temperature, fecal coliforms, dissolved oxygen, biochemical oxygen demand, total suspended solids, nitrates, orthophosphates and pH. The results were found to be close to the average observed values for all parameters studied for both calibration and validation periods with percent bias values between − 26% and 23% for calibration and − 30% and 51% for validation for all parameters, with fecal coliforms showing the highest deviation. The model revealed a poor water quality in Lena River for the entire simulation period, according to the Council Directive concerning the surface water quality intended for drinking water abstraction in the Member States (75/440/EEC). Fecal coliforms, orthophosphates and nitrates were found to be 99, 82 and 46% above the limit established in the Directive. HSPF was used to predict the impact of point and nonpoint pollution sources on the water quality of Lena River. Winter and summer scenarios were also addressed to evaluate water quality in high and low flow conditions. A maximum daily load was calculated to determine the reduction needed to comply with the Council Directive 75/440/EEC. The study showed that Lena River is fairly polluted calling for awareness at behavioral change of waste management in order to prevent the escalation of these effects with especially attention to fecal coliforms. - Highlights: • An integrated hydrological and water quality model for river management is presented. • An insight into the

  1. People of the ancient rainforest: late Pleistocene foragers at the Batadomba-lena rockshelter, Sri Lanka.

    Science.gov (United States)

    Perera, Nimal; Kourampas, Nikos; Simpson, Ian A; Deraniyagala, Siran U; Bulbeck, David; Kamminga, Johan; Perera, Jude; Fuller, Dorian Q; Szabó, Katherine; Oliveira, Nuno V

    2011-09-01

    Batadomba-lena, a rockshelter in the rainforest of southwestern Sri Lanka, has yielded some of the earliest evidence of Homo sapiens in South Asia. H. sapiens foragers were present at Batadomba-lena from ca. 36,000 cal BP to the terminal Pleistocene and Holocene. Human occupation was sporadic before the global Last Glacial Maximum (LGM). Batadomba-lena's Late Pleistocene inhabitants foraged for a broad spectrum of plant and mainly arboreal animal resources (monkeys, squirrels and abundant rainforest snails), derived from a landscape that retained equatorial rainforest cover through periods of pronounced regional aridity during the LGM. Juxtaposed hearths, palaeofloors with habitation debris, postholes, excavated pits, and animal and plant remains, including abundant Canarium nutshells, reflect intensive habitation of the rockshelter in times of monsoon intensification and biome reorganisation after ca. 16,000 cal BP. This period corresponds with further broadening of the economic spectrum, evidenced though increased contribution of squirrels, freshwater snails and Canarium nuts in the diet of the rockshelter occupants. Microliths are more abundant and morphologically diverse in the earliest, pre-LGM layer and decline markedly during intensified rockshelter use on the wane of the LGM. We propose that changing toolkits and subsistence base reflect changing foraging practices, from shorter-lived visits of highly mobile foraging bands in the period before the LGM, to intensified use of Batadomba-lena and intense foraging for diverse resources around the site during and, especially, following the LGM. Traces of ochre, marine shell beads and other objects from an 80 km-distant shore, and, possibly burials reflect symbolic practices from the outset of human presence at the rockshelter. Evidence for differentiated use of space (individual hearths, possible habitation structures) is present in LGM and terminal Pleistocene layers. The record of Batadomba-lena demonstrates

  2. Methodology of experimental search for neutrinos from solar flares in Borexino detector

    Science.gov (United States)

    Atroshchenko, V. S.; Borodikhina, L. A.; Toropova, M. A.

    2017-01-01

    Solar flares are sudden variations in brightness observed near the Sun’s surface. Some theoretical models predict production of electron and muon neutrinos with energies up to few tens of MeV during solar flares. In 1980s the Homestake experiment reported excess of detected neutrino events possibly correlated with large solar flares. Since then the interest to similar studies by other neutrino detectors has increased. In this report we summarize the status of experimental searches and describe the methodology for the study of neutrinos from solar flares in Borexino liquid scintillator detector.

  3. Determination of the time resolution for neutron scintillation detectors by multi-coincidence measurement

    Institute of Scientific and Technical Information of China (English)

    LI Yong-Ming; RUAN Xi-Chao; ZHOU Sin; MA Zhong-Yuan

    2011-01-01

    Based on the multi-coincidence measurement, the time resolution of three liquid scintillation detectors (BC501A) were determined strictly by solving the coincidence equations, where the influence from electronics estimated by self coincidence measurement as well as the background had been considered. The result of this work agreed well with the result that was deduced from the traditional method, and it will be helpful to analyze the energy resolution of neutron time of flight spectra measured by using such detectors at CIAE (China Institute of Atomic Energy).

  4. Evaluation of the uncertainty for the efficiency curve determination of {sup 210}Pb by liquid scintillation; Avaliacao da incerteza para a curva de eficiencia da determinacao de {sup 210}Pb por cintilacao liquida

    Energy Technology Data Exchange (ETDEWEB)

    Sampaio, C.S.; Sousa, W.O.; Dantas, B.M., E-mail: camilla@ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    Methodologies for the evaluation of uncertainties associated with the determination of the efficiency curve of {sup 210}Pb by liquid scintillation counting (LSC) are presented. No statistical difference were found when compared the uncertainties of the curves that represented the counting net before and after the secular equilibrium between {sup 210}Pb and {sup 210}Bi, nether when compared the curves when counting only {sup 210}Pb and the curve with the total count of {sup 210}Pb and {sup 210}Bi, for the same time interval after precipitation. (author)

  5. Liquid scintillation counting standardization of 125I in organic and inorganic samples by the CIEMAT/NIST method; Calibracion por centelleo liquido del 125I en muestras inorganicas y organicas, mediante el metodo CIEMAT/NIST

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J. M.; Grau Carles, A.

    1994-07-01

    The liquid scintillation counting standardization of organic and inorganic samples of ''I25I by the CIEMAT/NIST method using five different scintillators is described. The discrepancies between experimental and computed efficiencies are lower than 1.4% and 1.7%, for inorganic and organic samples, respectively, in the interval 421-226 of quenching parameter. Both organic and inorganic solutions have been standardized in terms of activity concentration to an overall uncertainty of 0.76%. (Author) 14 refs.

  6. Neutron detector array at IUAC: Design features and instrumentation developments

    Indian Academy of Sciences (India)

    P Sugathan; A Jhingan; K S Golda; T Varughese; S Venkataramanan; N Saneesh; V V Satyanarayana; S K Suman; J Antony; Ruby Shanti; K Singh; S K Saini; A Gupta; A Kothari; P Barua; Rajesh Kumar; J Zacharias; R P Singh; B R Behera; S K Mandal; I M Govil; R K Bhowmik

    2014-11-01

    The characteristics and performance of the newly commissioned neutron detector array at IUAC are described. The array consists of 100 BC501 liquid scintillators mounted in a semispherical geometry and are kept at a distance of 175 cm from the reaction point. Each detector is a 5″ × 5″ cylindrical cell coupled to 5″ diameter photomultiplier tube (PMT). Signal processing is realized using custom-designed home-made integrated electronic modules which perform neutron–gamma discrimination using zero cross timing and time-of-flight (TOF) technique. Compact custom-built high voltage power supply developed using DC–DC converters are used to bias the detector. The neutrons are recorded in coincidence with fission fragments which are detected using multi-wire proportional counters mounted inside a 1m diameter SS target chamber. The detectors and electronics have been tested off-line using radioactive sources and the results are presented.

  7. Development of a quasi-monoenergetic neutron field and measurements of the response function of an organic liquid scintillator for the neutron energy range from 66 to 206 MeV

    CERN Document Server

    Nakao, N; Nakamura, T; Uwamino, Y

    2002-01-01

    A quasi-monoenergetic neutron field was developed using a thin sup 7 Li target bombarded by protons in the energy range from 70 to 210 MeV at the RIKEN ring cyclotron facility. The neutron energy spectra were measured with an NE213 organic liquid scintillator using the TOF method. The absolute peak neutron yields were obtained by measurements of 478 keV gamma-rays from sup 7 Be nuclei produced in a sup 7 Li target through the sup 7 Li( p,n) sup 7 Be (g.s.+0.429 MeV) reaction. Using the neutron field, the absolute values of the neutron response functions of a 12.7 cm diameter by 12.7 cm long NE213 organic liquid scintillator were measured, and were compared with calculations using a Monte Carlo code developed by Cecil et al. The measured response functions without any wall-effect events were also obtained, and compared with calculations using a modified Monte Carlo code. Comparisons between a measurement and a calculation both with and without any wall-effect events gave a good agreement.

  8. Hybrid Extensive Air Shower Detector Array at the University of Puebla to Study Cosmic Rays

    Science.gov (United States)

    Martínez, O.; Pérez, E.; Salazar, H.; Villaseñor, L.

    We describe the design of an extensive air shower detector array built in the Campus of the University of Puebla (located at 19°N, 90°W, 800 gcm -2) to measure the energy and arrival direction of primary cosmic rays with energies around 1015 eV. The array consists of 18 liquid scintillator detectors (12 in the first stage) and 6 water Cherenkov detectors (one of 10 m 2 cross section and five smaller ones of 1.86 m 2 cross section), distributed in a square grid with a detector spacing of 20 m over an area of 4000 m 2. In this paper we discuss the calibration and stability of the array, and discuss the capability of hybrid arrays, such as this one consisting of water Cherenkov and liquid scintillator detectors, to allow a separation of the electromagnetic and muon components of extensive air showers. This separation plays an important role in the determination of the mass and identity of the primary cosmic ray. This facility is also used to train students interested in the field of cosmic rays.

  9. A time-series analysis of flood disaster around Lena river using Landsat TM/ETM+

    Science.gov (United States)

    Sakai, Toru; Hatta, Shigemi; Okumura, Makoto; Takeuchi, Wataru; Hiyama, Tetsuya; Inoue, Gen

    2010-05-01

    Landsat satellite has provided a continuous record of earth observation since 1972, gradually improving sensors (i.e. MSS, TM and ETM+). Already processed archives of Landsat image are now available free of charge from the internet. The Landsat image of 30 m spatial resolution with multiple spectral bands between 450 and 2350 nm is appropriate for detailed mapping of natural resource at wide geographical areas. However, one of the biggest concerns in the use of Landsat image is the uncertainty in the timing of acquisitions. Although detection of land cover change usually requires acquisitions before and after the change, the Landsat image is often unavailable because of the long-term intervals (16 days) and variation in atmosphere. Nearly cloud-free image is acquired at least once per year (total of 22 or 23 scenes per year). Therefore, it may be difficult to acquire appropriate images for monitoring natural disturbances caused at short-term intervals (e.g., flood, forest fire and hurricanes). Our objectives are: (1) to examine whether a time-series of Landsat image is available for monitoring a flood disaster, and (2) to evaluate the impact and timing of the flood disaster around Lena river in Siberia. A set of Landsat TM/ETM+ satellite images was used to enable acquisition of cloud-free image, although Landsat ETM+ images include failure of the Scan Line Corrector (SLC) from May 2003. The overlap area of a time series of 20 Landsat TM/ETM+ images (path 120-122, row 17) from April 2007 to August 2007 was clipped (approximately 33 km × 90 km), and the other area was excluded from the analyses. Image classification was performed on each image separately using an unsupervised ISODATA method, and each Landsat TM/ETM+ image was classified into three land cover types: (1) ice, (2) water, and (3) land. From three land cover types, the area of Lena river was estimated. The area of Lena river dramatically changed after spring breakup. The middle part of Lena river around

  10. Characterisation of Fe-bearing particles and colloids in the Lena River basin, NE Russia

    Science.gov (United States)

    Hirst, Catherine; Andersson, Per S.; Shaw, Samuel; Burke, Ian T.; Kutscher, Liselott; Murphy, Melissa J.; Maximov, Trofim; Pokrovsky, Oleg S.; Mörth, Carl-Magnus; Porcelli, Don

    2017-09-01

    Rivers are significant contributors of Fe to the ocean. However, the characteristics of chemically reactive Fe remain poorly constrained, especially in large Arctic rivers, which drain landscapes highly susceptible to climate change and carbon cycle alteration. The aim of this study was a detailed characterisation (size, mineralogy, and speciation) of riverine Fe-bearing particles (>0.22 μm) and colloids (1 kDa-0.22 μm) and their association with organic carbon (OC), in the Lena River and tributaries, which drain a catchment almost entirely underlain by permafrost. Samples from the main channel and tributaries representing watersheds that span a wide range in topography and lithology were taken after the spring flood in June 2013 and summer baseflow in July 2012. Fe-bearing particles were identified, using Transmission Electron Microscopy, as large (200 nm-1 μm) aggregates of smaller (20-30 nm) spherical colloids of chemically-reactive ferrihydrite. In contrast, there were also large (500 nm-1 μm) aggregates of clay (illite) particles and smaller (100-200 nm) iron oxide particles (dominantly hematite) that contain poorly reactive Fe. TEM imaging and Scanning Transmission X-ray microscopy (STXM) indicated that the ferrihydrite is present as discrete particles within networks of amorphous particulate organic carbon (POC) and attached to the surface of primary produced organic matter and clay particles. Together, these larger particles act as the main carriers of nanoscale ferrihydrite in the Lena River basin. The chemically reactive ferrihydrite accounts for on average 70 ± 15% of the total suspended Fe in the Lena River and tributaries. These observations place important constraints on Fe and OC cycling in the Lena River catchment area and Fe-bearing particle transport to the Arctic Ocean.

  11. Integrated hydrological and water quality model for river management: a case study on Lena River.

    Science.gov (United States)

    Fonseca, André; Botelho, Cidália; Boaventura, Rui A R; Vilar, Vítor J P

    2014-07-01

    The Hydrologic Simulation Program FORTRAN (HSPF) model was used to assess the impact of wastewater discharges on the water quality of a Lis River tributary (Lena River), a 176 km(2) watershed in Leiria region, Portugal. The model parameters obtained in this study, could potentially serve as reference values for the calibration of other watersheds in the area or with similar climatic characteristics, which don't have enough data for calibration. Water quality constituents modeled in this study included temperature, fecal coliforms, dissolved oxygen, biochemical oxygen demand, total suspended solids, nitrates, orthophosphates and pH. The results were found to be close to the average observed values for all parameters studied for both calibration and validation periods with percent bias values between -26% and 23% for calibration and -30% and 51% for validation for all parameters, with fecal coliforms showing the highest deviation. The model revealed a poor water quality in Lena River for the entire simulation period, according to the Council Directive concerning the surface water quality intended for drinking water abstraction in the Member States (75/440/EEC). Fecal coliforms, orthophosphates and nitrates were found to be 99, 82 and 46% above the limit established in the Directive. HSPF was used to predict the impact of point and nonpoint pollution sources on the water quality of Lena River. Winter and summer scenarios were also addressed to evaluate water quality in high and low flow conditions. A maximum daily load was calculated to determine the reduction needed to comply with the Council Directive 75/440/EEC. The study showed that Lena River is fairly polluted calling for awareness at behavioral change of waste management in order to prevent the escalation of these effects with especially attention to fecal coliforms.

  12. Lena Delta hydrology and geochemistry: long-term hydrological data and recent field observations

    OpenAIRE

    Fedorova, I.; Chetverova, A; Bolshiyanov, D.; A. Makarov; J. Boike; B. Heim; Morgenstern, A; Overduin, P. P.; C. Wegner; Kashina, V.; Eulenburg, A.; Dobrotina, E.; Sidorina, I.

    2015-01-01

    The Lena River forms one of the largest deltas in the Arctic. We compare two sets of data to reveal new insights into the hydrological, hydrochemical, and geochemical processes within the delta: (i) long-term hydrometric observations at the Khabarova station at the head of the delta from 1951 to 2005; (ii) field hydrological and geochemical observations carried out within the delta since 2002. Periods with differing relative discharge and intensity of fluvial processes were identified from th...

  13. COS FUV Detector Response to New HV Management System at LP3 {LENA4}

    Science.gov (United States)

    Penton, Steven

    2013-10-01

    This program uses a series of 205s WAVECALS and 60s DCE dumps to exercise the new HV Management System. We first ramp to the Maximum HV for Both Segment FUVA/FUVB = 178/175, we then transition to the minimum HV {A/B = 167/163} using the new HV management system, then transition back to the Maximum HV. The WAVECAL exposures at the Maximum HV will be taken with G160M/1611 {C1611} and the minimums are taken with G160M/1623 {C1623}. The CENWAVE change is required to allow time for the HV change. The sequence is repeated with FUVA ON {FUVB OFF}, and then with FUVB ON {FUVA OFF}. DCE Dumps are included before and after each WAVECAL.All exposures in the program should execute at the LP3 position, using the ALTERNATE lifetime position.This program will use a special HV Table with the following changes to the normal HV/Aperture table:CENWAVE Lifetime Position HVA/HVB--------------------------1611 Alternate {LP3} 178/1751623 Alternate {LP3} 167/163LP3 FUV aperture positions and SIAF file updates are not absolutely required, as these are all internals, but they are desired.

  14. Lena River discharge events in sediments of Laptev Sea, Russian Arctic

    Science.gov (United States)

    Rivera, Janiel; Karabanov, Eugene B.; Williams, Douglas F.; Buchinskyi, Valeryi; Kuzmin, Michael

    2006-01-01

    To reconstruct the variability of freshwater discharge to the Arctic via the Lena River, 22 gravity cores were collected along two transects that extend from the delta floodplain onto the Laptev Sea shelf. High magnetic susceptibility (MS) signals appear to be good indicators for river sediment deposition. Sedimentation of this terrestrial material forms fluvial units distinguished by coarse grain size and high MS signal produced by the magnetic properties from the river-derived material. The criteria to distinguish marine units are low magnetic susceptibility signals when compared with fluvial units, lithological descriptions and granulometric analyses. Sedigraph granulometric analyses in combination with wet sieving analyses (grain size > 4 Φ) reveal changes in grain-size distributions along the cores that are well correlated with magnetic susceptibility data. Fluvial and marine units were found to alternate sequentially along the cores. Data from cores comprising two transects in the Laptev Sea revealed 17 total fluvial events during the last 2000 years. The Lena River-derived sediment bedload could be traced 34.5-47.5 km far from the delta edge of Bykovskaya branch showing direct impact of Lena River discharge to the Laptev Sea.

  15. Improving the time response of a gamma/neutron liquid detector

    Science.gov (United States)

    Malone, Robert M.; Buckles, Robert A.; DeYoung, Anemarie; Garza, Irene; Frayer, Daniel K.; Kaufman, Morris I.; Morgan, George L.; Obst, Andrew W.; Rundberg, Robert S.; Tinsley, Jim; Waltman, Tom B.; Yuan, Vincent W.

    2016-09-01

    A pulsed neutron source is used to interrogate a target, producing secondary gammas and neutrons. In order to make good use of the relatively small number of gamma rays that emerge from the system after the neutron flash, our detector system must be both efficient in converting gamma rays to a detectable electronic signal and reasonably large in volume. Isotropic gamma rays are emitted from the target. These signals are converted to light within a large chamber of a liquid scintillator. To provide adequate time-of-flight separation between the gamma and neutron signals, the liquid scintillator is placed meters away from the target under interrogation. An acrylic PMMA (polymethyl methacrylate) light guide directs the emission light from the chamber into a 5-inch-diameter photomultiplier tube. However, this PMMA light guide produces a time delay for much of the light. Illumination design programs count rays traced from the source to a receiver. By including the index of refraction of the different materials that the rays pass through, the optical power at the receiver is calculated. An illumination design program can be used to optimize the optical material geometries to maximize the ray count and/or the receiver power. A macro was written to collect the optical path lengths of the rays and import them into a spreadsheet, where histograms of the time histories of the rays are plotted. This method allows optimization on the time response of different optical detector systems. One liquid scintillator chamber has been filled with a grid of reflective plates to improve its time response. Cylindrical detector geometries are more efficient.

  16. NOvA detector technology with intial performance from the surface prototype

    Energy Technology Data Exchange (ETDEWEB)

    Muether, M.; /Fermilab

    2011-09-01

    NOvA, the NuMI Off-Axis {nu}{sub e} Appearance experiment, will study {nu}{sub {mu}} {yields} {nu}{sub e} oscillations characterized by the mixing angle {Theta}{sub 13}. Provided {Theta}{sub 13} is large enough, NOvA may ultimately determine the ordering of the neutrino masses and measure CP violation in neutrino oscillations. A complementary pair of detectors will be constructed {approx}14 mrad off beam axis to optimize the energy profile of the neutrinos. This system consists of a surface based 14 kTon liquid scintillator tracking volume located 810 km from the main injector source (NuMI) in Ash River, Minnesota and a smaller underground 222 Ton near detector at the Fermilab. The first neutrino signals at the Ash River Site are expected prior to the 2012 accelerator shutdown. In the meantime, a near detector surface prototype has been completed and neutrinos from two Fermilab sources have been observed using the same highly segmented PVC and liquid scintillator detector system that will be deployed in the full scale experiment. Design and initial performance characteristics of this prototype system are being fed back into the design for the full NOvA program.

  17. New C$_{6}$D$_{6}$ detectors: reduced neutron sensitivity and improved safety

    CERN Document Server

    Mastinu, Pierfrancesco; Berthoumieux, Eric; Cano-Ott, Daniel; Gramegna, F; Guerrero, Carlos; Massimi, Cristian; Milazzo, Paolo Maria; Mingrone, Federica; Praena, Javier; Prete, G; García, Aczel Regino

    2013-01-01

    During the 2011 data measurement campaign at n_TOF, the liquid scintillator detectors developed at FZK-Karlsruhe (hereafter named K6D6, [1]) and used with success along 10 years have shown ageing problems, mainly related to liquid leakage. The mould used to produce the carbon fiber structure, containing the liquid and the detection elements, was not available anymore and the technician involved in its construction was retired. Once decided to proceed to the production of new detectors (L6D6 in the following) two major items have been identified: - The detector setup must be able to work in the new class A experimental area (safety requirements advise to avoid the use of the old K6D6 in this area). - If possible, it is useful to reduce the neutron sensitivity, with the aim to have a liquid scintillator detector with very low neutron sensitivity (improving the already high performing K6D6). [1] R.Plag et al., NIM A496 (2003) 425

  18. A comparative study of 19-iodo cholesterol-125I 3-acetate and Na 125I in liquid scintillation measurements; Estudio comparativo del acetato de 19-iodocolesterol- -125I con Nal25I en medidas por centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J. M.; Grau Carles, A.

    1994-07-01

    A comparative study of performance of 19-iodo cholesterol {sup 1}25I 3-acetate and sodium iodide samples labeled with 125I is presented for liquid scintillation counting measurements. Quench effect, count rate stability and spectral evolution of samples have been followed for several weeks in Toluene, Hisafe II, Instagel, Dioxane-naphthalene and Toluene-alcohol scintillators. Organic samples have negligible quench effect in the interval of I concentration of 0-90 {mu}g and inorganic samples only show a very small variation, lower than 12%, for Dioxane-naphthalene, in the same range of concentration. Satisfactory stability is obtained in general for both, organic and inorganic samples, but small counting losses, 0.03% for 19-iodocholesterol 1 I 3-acetate samples in Tolue ne-alcohol and 0 .04% for Na 125I samples in Dioxane-naphthalene and Toluene-alcohol, have been reported. (Author) 8 refs.

  19. Phytoplankton community structure in the Lena Delta (Siberia, Russia in relation to hydrography

    Directory of Open Access Journals (Sweden)

    A. C. Kraberg

    2013-02-01

    Full Text Available The Lena Delta in Northern Siberia is one of the largest river deltas in the world. During peak discharge, after the ice melt in spring, it delivers between 60–8000 m3s−1 of water and sediment into the Arctic Ocean. The Lena Delta and the Laptev Sea coast also constitute a~continuous permafrost region. Ongoing climate change, which is particularly pronounced in the Arctic, is leading to increased rates of permafrost thaw. This is likely to profoundly change the discharge rates of the Lena River and the chemistry of the river waters which are discharged into the coastal Laptev Sea, e.g. by increasing concentrations of inorganic nutrients, DOC and importantly methane. These physical and chemical changes will also affect the composition of and interactions between phytoplankton and zooplankton communities, forming the basis of the food web. However, before potential consequences of climate change for coastal arctic plankton communities can be judged, the inherent status of the diversity and linked foodweb interactions within the delta need to be established. As part of the AWI Lena Delta Programme in 2010 the phyto- and microzooplankton community in three river channels as well as four coastal transects were investigated to capture the typical river phytoplankton communities and the transitional zone of brackish/marine conditions. Most CTD profiles from 23 coastal stations showed very strong stratification. The only exception to this was a small a shallow and mixed area running from the outflow of Bykovskaya channel in a northerly direction parallel to the shore (transect 3. Of the five stations in this area three had a salinity of close to zero. Two further stations had salinities of around 2 and 5 throughout the water column. In the remaining transects on the other hand salinities varied between 5–30 with depth. Phytoplankton counts from the outflow from the Lena were dominated by diatoms (Aulacoseira species

  20. The Lena River Delta Observatory, Arctic Siberia: a Contribution to the ESA DUE Permafrost Project

    Science.gov (United States)

    Heim, Birgit; Boike, Julia; Moritz, Langer; Annett, Bartsch; Sina, Muster; Jennifer, Sobiech; Konstanze, Piel; Günter, Stoof; Anne, Morgenstern; Mathias, Ulrich

    2010-05-01

    The major task of the ESA Data User Element DUE PERMAFROST is to develop and use Earth Observation services specifically for monitoring and modelling of permafrost. In order to setup the required information services, a target area approach with specified case study regions is used. Long-term ground data series and multidisciplinary ongoing projects make the Lena River delta (Arctic Siberia) a prime study region for evaluation and validation of the DUE PERMAFROST remote sensing products. The Lena River Delta located in the zone of continuous permafrost is a key region for Arctic system science. Since 1998, the Alfred Wegener Institute for Polar and Marine Research AWI in collaboration with the Lena Delta Reserve in Tiksi has operated the German-Russian research station Samoylov. Relevant ground-based data (air temperature, radiation, snow, albedo, soil temperature and moisture) are collected continuously. The high landscape heterogeneity (wet polygonal centres, dry polygonal rims, ponds and lakes) challenges all ground data observations. Match-up data sets of ground data and remote sensing products coincident in time and location are being built up. Exclusion and selection criteria will be based on experience, especially the knowledge on parameter variability in time and space. The main focus are the remote sensing products ‘surface temperature', ‘surface moisture', ‘albedo', ‘vegetation' and ‘water'. Statistical and contextural methods will be used for the upscaling from the plot to the meso-scale. Problems will have to be identified such as process-dependent scales and the water body ratio within the pixel.

  1. Theoretical simulation and experimental research of the light output function of liquid scintillator EJ339A%EJ339A型液体闪烁探测系统光输出响应函数的理论模拟与实验研究

    Institute of Scientific and Technical Information of China (English)

    王亭亭; 王亮; 莫钊洪; 赵德山; 熊忠华

    2016-01-01

    对液体闪烁探测器EJ339A中子与伽马辐射测量问题,采用理论模拟与实验分析方法,结合自主设计搭建的基于LabVIEW的数字化信号处理系统,分别完成22Na、133Ba、137Cs和60Co等4种不同能量的γ源等效电子能量测量与刻度。在此基础上,利用中子飞行时间测量原理,在不同时间窗下将锎(252Cf)源近似分化成若干个单能中子源,获得1.9‒7.8 MeV范围内中子在探测器中的光输出响应函数。结果表明,理论模拟与实验测量值在低能段比较吻合,而高能段存在约7.3%的误差。%Background: The light output function is an elementary aspect for neutron spectrometry measured by an organic scintillator to unfold the neutron spectrum from the pulse height distribution.Purpose: This paper aims to investigate the properties of a boron-loaded liquid scintillator EJ339A, using photon sources and neutrons from a 252Cf source.Methods: The light output was defined using Compton electron spectra. Pulse shape discrimination (PSD) and time of flight (TOF) were used to distinguish neutron andg-rays. Combining theoretical modeling and experimental research, four different gamma sources are applied to achieve equivalent calibration of electronic energy, namely22Na,133Ba,137Cs, and60Co, respectively. Accordingly, based on TOF method,252Cf, a spontaneous fission neutron source, is treated as several quasi-monoenergetic neutron sources under different time-windows.Results: The electron light output scale was calibrated by the measured detector response. Neutrons deposit energy in the detector and give a light output function with the neutron energy in the range of 1.9‒7.8MeV.Conclusion: It shows that experimental data of light output function are in good agreement with simulation result in the low energy section, while discrepancies arise in the high energy section.

  2. The MACRO detector at Gran Sasso

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio, M.; Antolini, R.; Assiro, R.; Auriemma, G.; Bakari, D.; Baldini, A.; Barbarino, G.C.; Barbarito, E.; Barish, B.C.; Battistoni, G.; Becherini, Y.; Bellotti, R.; Bemporad, C.; Bernardini, P. E-mail: paolo.bernardini@le.infn.it; Bilokon, H.; Bisi, V.; Bloise, C.; Bottazzi, E.; Bower, C.; Brigida, M.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, D.; Candela, A.; Carboni, M.; Cecchini, S.; Cei, F.; Ceres, A.; Chiarella, V.; Choudhary, B.C.; Coutu, S.; Cozzi, M.; Creti, P.; De Cataldo, G.; Esposti, L.D.L. Degli; Dekhissi, H.; Marzo, C. De; Mitri, I. De; Derkaoui, J.; Vincenzi, M. De; Credico, A. Di; Ferdinando, D. Di; Diotallevi, R.; Erriquez, O.; Favuzzi, C.; Forti, C.; Fusco, P.; Gebhard, M.; Giacomelli, G.; Giacomelli, R.; Giannini, G.; Giglietto, N.; Giorgini, M.; Giuliani, R.; Goretti, M.; Grassi, M.; Grau, H.; Gray, L.; Grillo, A.; Guarino, F.; Gustavino, C.; Habig, A.; Hanson, J.; Hanson, K.; Hawthorne, A.; Heinz, R.; Hong, J.T.; Iarocci, E.; Katsavounidis, E.; Katsavounidis, I.; Kearns, E.; Kim, H.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Leone, A.; Levin, D.S.; Lipari, P.; Liu, G.; Liu, R.; Longley, N.P.; Longo, M.J.; Loparco, F.; Maaroufi, F.; Mancarella, G.; Mandrioli, G.; Manzoor, S.; Marrelli, V.; Margiotta, A.; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M.N.; Michael, D.G.; Mikheyev, S.; Miller, L.; Monacelli, P.; Mongelli, M.; Montaruli, T.; Monteno, M.; Mossbarger, L.; Mufson, S.; Musser, J.; Nicolo, D.; Nolty, R.; Okada, C.; Orsini, M.; Orth, C.; Osteria, G.; Ouchrif, M.; Palamara, O.; Parlati, S.; Patera, V.; Patrizii, L.; Pazzi, R.; Peck, C.W. E-mail: peck@hep.caltech.edu; Pellizzoni, G.; Perchiazzi, M.; Perrone, L.; Petrakis, J.; Petrera, S.; Pignatano, N.; Pinto, C.; Pistilli, P.; Popa, V.; Raino, A.; Reynoldson, J.; Ronga, F.; Rrhioua, A.; Sacchetti, A.; Saggese, P.; Satriano, C.; Satta, L.; Scapparone, E.; Scholberg, K.; Sciubba, A.; Serra, P.; Sioli, M.; Sirri, G.; Sitta, M.; Sondergaard, S.; Spinelli, P.[and others

    2002-07-01

    MACRO was an experiment that ran in the Laboratori Nazionali del Gran Sasso from 1988 to 2000. Its principal goal was to observe magnetic monopoles or set significantly lower experimental flux limits than had been previously available in the velocity range from about {beta}=10{sup -4} to unity. In addition it made a variety of other observations. Examples are: setting flux limits on other so far unobserved particles such as nuclei and lightly ionizing particles, searching for WIMP annihilations in the Earth and the Sun and for neutrino bursts from stellar collapses in or near our Galaxy, and making measurements relevant to high energy muon and neutrino astronomy and of the flux of up-going muons as a function of nadir angle showing evidence for neutrino oscillations. The apparatus consisted of three principal types of detectors: liquid scintillator counters, limited streamer tubes, and nuclear track etch detectors. In addition, over part of its area it contained a transition radiation detector. The general design philosophy emphasized redundancy and complementarity. This paper describes the technical aspects of the complete MACRO detector, its operational performance, and the techniques used to calibrate it and verify its proper operation. It supplements a previously published paper which described the first portion of the detector that was built and operated.

  3. Transient modeling of the ground thermal conditions using satellite data in the Lena River delta, Siberia

    Science.gov (United States)

    Westermann, Sebastian; Peter, Maria; Langer, Moritz; Schwamborn, Georg; Schirrmeister, Lutz; Etzelmüller, Bernd; Boike, Julia

    2017-06-01

    Permafrost is a sensitive element of the cryosphere, but operational monitoring of the ground thermal conditions on large spatial scales is still lacking. Here, we demonstrate a remote-sensing-based scheme that is capable of estimating the transient evolution of ground temperatures and active layer thickness by means of the ground thermal model CryoGrid 2. The scheme is applied to an area of approximately 16 000 km2 in the Lena River delta (LRD) in NE Siberia for a period of 14 years. The forcing data sets at 1 km spatial and weekly temporal resolution are synthesized from satellite products and fields of meteorological variables from the ERA-Interim reanalysis. To assign spatially distributed ground thermal properties, a stratigraphic classification based on geomorphological observations and mapping is constructed, which accounts for the large-scale patterns of sediment types, ground ice and surface properties in the Lena River delta. A comparison of the model forcing to in situ measurements on Samoylov Island in the southern part of the study area yields an acceptable agreement for the purpose of ground thermal modeling, for surface temperature, snow depth, and timing of the onset and termination of the winter snow cover. The model results are compared to observations of ground temperatures and thaw depths at nine sites in the Lena River delta, suggesting that thaw depths are in most cases reproduced to within 0.1 m or less and multi-year averages of ground temperatures within 1-2 °C. Comparison of monthly average temperatures at depths of 2-3 m in five boreholes yielded an RMSE of 1.1 °C and a bias of -0.9 °C for the model results. The highest ground temperatures are calculated for grid cells close to the main river channels in the south as well as areas with sandy sediments and low organic and ice contents in the central delta, where also the largest thaw depths occur. On the other hand, the lowest temperatures are modeled for the eastern part, which is an

  4. Oedipus in Brooklyn: reading Freud on women, watching Lena Dunham's girls.

    Science.gov (United States)

    Buchberg, Lisa

    2014-01-01

    Through an examination of Freud's Lecture 33, "Femininity" (1933), and "Mourning and Melancholia" (1917), the author proposes a reading of Freud's description of the girl becoming a woman. Female development is retold as a melancholic narrative-one in which the girl's entrance into the positive Oedipus is founded on unconscious grievance and unmourned loss of the early relationship with her mother. Castration and penis envy are reconceived as melancholic markers-the manifest content of the subjectivity of refusal, loss, and imagined repair of the early maternal relationship. Lena Dunham's HBO television series Girls is analyzed as an illustration of these theoretical understandings. © 2014 The Psychoanalytic Quarterly, Inc.

  5. Neutrino-4 experiment on search for sterile neutrino with multi-section model of detector

    CERN Document Server

    Serebrov, A P; Samoilov, R M; Fomin, A K; Zinoviev, V G; Neustroev, P V; Golovtsov, V L; Gruzinskiy, N V; Solovey, V A; Chernyj, A V; Zherebtsov, O M; Martemyanov, V P; Tsynoev, V G; Tarasenkov, V G; Aleshin, V I; Petelin, A L; Ishutov, A L; Tuzov, A A; Sazontov, S A; Ryazanov, D K; Gromov, M O; Afanasiev, V V; Zaytsev, M E; Chaikovskii, M E

    2016-01-01

    In order to carry out research in the field of possible existence of sterile neutrino the laboratory based on SM-3 reactor (Dimitrovgrad, Russia) was created to search for oscillations of reactor antineutrino. The prototype of a multi-section neutrino detector with liquid scintillator volume of 350 l was installed in the middle of 2015. It is a moveable inside the passive shielding detector, which can be set at distance range from 6 to 11 meters from the reactor core. The measurements of antineutrino flux at such small distances from the reactor core carried out for the first time. The different methods of cosmic background suppression were researched in order to increase the precision of the experiment. After collecting data for half a year, measurement accuracy for the nearest point (6.5 m) comprised 10%. The full-scale detector with volume of liquid scintillator 3 m3 (5x10 sections) is at the stage of preparation. It will allow us to obtain up to 1.5-3.0% statistic accuracy of measurements at the distances...

  6. A Deuterated Neutron Detector Array For Nuclear (Astro)Physics Studies

    Science.gov (United States)

    Almaraz-Calderon, Sergio; Asher, B. W.; Barber, P.; Hanselman, K.; Perello, J. F.

    2016-09-01

    The properties of neutron-rich nuclei are at the forefront of research in nuclear structure, nuclear reactions and nuclear astrophysics. The advent of intense rare isotope beams (RIBs) has opened a new door for studies of systems with very short half-lives and possible fascinating properties. Neutron spectroscopic techniques become increasingly relevant when these neutron rich nuclei are used in a variety of experiments. At Florida State University, we are developing a neutron detector array that will allow us to perform high-resolution neutron spectroscopic studies with stable and radioactive beams. The neutron detection system consists of 16 deuterated organic liquid scintillation detectors with fast response and pulse-shape discrimination capabilities. In addition to these properties, there is the potential to use the structure in the pulse-height spectra to extract the energy of the neutrons and thus produce directly excitation spectra. This type of detector uses deuterated benzene (C6D6) as the liquid scintillation medium. The asymmetric nature of the scattering between a neutron and a deuterium in the center of mass produces a pulse-height spectrum from the deuterated scintillator which contains useful information on the initial energy of the neutron. Work supported in part by the State of Florida and NSF Grant No. 1401574.

  7. Electronics for the Extensive Air Shower Detector Array at the University of Puebla

    Science.gov (United States)

    Pérez, E.; Conde, R.; Martínez, O.; Murrieta, T.; Salazar, H.; Villaseñor, L.

    2006-09-01

    In this paper we describe in detail the electronics cards that were designed to be the basis of the data acquisition system (DAS) of the extensive air shower detector array built in the Campus of the University of Puebla. The purpose of this observatory is to measure the energy and arrival direction of primary cosmic rays with energies around 1015 eV. The array consists of 18 liquid scintillator detectors (12 in the first stage) and 6 water Cherenkov detectors (one of 10 m2 cross section and five smaller ones of 1.86 m2 cross section), distributed in a square grid with a detector spacing of 20 m over an area of 4000 m2. The electronics described here uses analog to digital converters of 10 bits working at a sampling speed of 40 MS/s and field-programmable gate array (FPGA).

  8. ICESat-Derived Elevation Changes on the Lena Delta and Laptev Sea, Siberia

    Science.gov (United States)

    Muskett, Reginald

    2014-05-01

    We employ elevation data from the Ice, Cloud, and land Elevation Satellite (ICESat) Geoscience Laser Altimeter System (GLAS) to investigate surface changes across the Lena Delta and sea ice of the coastal Laptev Sea, Siberia during winters of 2003 through 2008. We compare ICESat GLAS-derived elevation changes on sea ice and the Bykovskaya and Sardakhskaya Channels with datum-corrected tide gauge height measurements from Danai, Sannikova and Tiksi stations. We find the coastal sea ice and large inland ice covered channels elevation changes are in phase with the tide-height changes on a same-month-year and datum controlled basis. Furthermore, we find elevation change on tundra drained lake basins to be +0.03 +/- 0.02 m, on average. These findings indicate ICESat GLAS is capable of detection of tide fluxes of ice covered coastal rivers and with a small error range is suitable for investigations of active-layer and permafrost dynamics associated with seasonal freezing (heave) and thawing (subsidence) using repeat-location profiles. Ref.: Muskett, R.R., "ICESat-Derived Elevation Changes on the Lena Delta and Laptev Sea, Siberia," Open Journal of Modern Hydrology, 4 (1), pp. 1-9, 2014. http://www.scirp.org/journal/PaperDownload.aspx?paperID=41709.

  9. Fluvial thermal erosion during the ice break-up of the Lena river (Siberia)

    Science.gov (United States)

    Costard, F.; Gautier, E.; Fedorov, A.; Konstantinov, P.; Dupeyrat, L.

    2012-04-01

    The Lena River is one of the largest Arctic rivers; its periglacial environment implies an excessive fluvial regime and a spectacular flood occurring at the end of the winter. From the beginning of November to May, a continuous ice cover can be observed as thick as 2 m on the Lena River in Central Siberia. The break up starts around May 15 at the latitude of Yakutsk, corresponding to a flood wave coming from the South and to an increase of the water stream temperature up to 18°C. In spite of a relatively good understanding of the initial stage of the breakup period of these periglacial rivers [Beltaos and Burrell, 2002; Shen, 2003; Billfalk, 1982], only a few studies report on the role of mechanical and thermal erosion during the breakup Observations and measurements of erosion of the island heads during the first days of the ice breakup were made during breakup periods over a 4-year period (2008-2011). Here, we reassess the efficiency of the fluvial thermal erosion using both high resolution records from field measurements and modeling. We analyze the impact of the breakup on the erosional process on the head of several fluvial islands. Only a few days are enough to produce erosion rate as high as 30 m. The protective effect of the ice cover at the very beginning of the break up has been studied in more detailed during 3 field trips. These values are relatively high but are in good agreement with our modeling.

  10. Exploring the Acceptability of Innovative Technology: A Pilot Study Using LENA with Parents of Young Deaf Children in the UK

    Science.gov (United States)

    Allen, Sarah; Crawford, Paul; Mulla, Imran

    2017-01-01

    Early intervention is widely recommended for children at risk of difficulties with speech, language and communication. Evidence for effective practice remains limited due in part to inherent difficulties in defining complex interventions and measuring change. The innovative Language Environment Analysis (LENA) system has exciting potential for…

  11. Improvements in apparatus and procedures for using an organic liquid scintillator as a fast-neutron spectrometer for radiation protection applications

    Energy Technology Data Exchange (ETDEWEB)

    Thorngate, J.H.

    1987-05-15

    For use in radiation protection measurements, a neutron spectrometer must have a wide energy range, good sensitivity, medium resolution, and ease of taking and reducing data. No single spectrometer meets all of these requirements. Several experiments aimed at improving and characterizing the detector response to gamma rays and neutrons were conducted. A light pipe (25 mm) was needed between the scintillator cell and the photomultiplier tube to achieve the best resolution. The light output of the scintillator as a function of gamma-ray energy was measured. Three experiments were conducted to determine the light output as a function of neutron energy. Monte Carlo calculations were made to evaluate the effects of multiple neutron scattering and edge effects in the detector. The electronic systems associated with the detector were improved with a transistorized circuit providing the bias voltage for the photomultiplier tube dynodes. This circuit was needed to obtain pulse-height linearity over the wide range of signal sizes. A special live-time clock was built to compensate for the large amount of dead time generated by the pulse-shape discrimination circuit we chose to use. 64 refs., 58 figs., 9 tabs.

  12. Hydrosweep Measurements During the Expedition ARK XX-2 to Lena Trough and Western Gakkel Ridge

    Science.gov (United States)

    Gauger, S.; Kohls, T.; Roeber, S.; Snow, J.

    2004-12-01

    The region of Lena Trough and Western Gakkel Ridge in the Arctic Ocean was the object of an expedition in the summer of 2004. This region is of particular geoscientific interest because of its extremely slow spreading rates and the variety of morphologic forms that are produced in this tectonic environment. Therefore, the multibeam measurement system was of particular importance to the scientific goals of the cruise. The main characteristic of the Hydrosweep DS-2 deep-water sounding system aboard RV Polarstern is the 90° or 120° coverage angle in which the seafloor is depicted with 59 specific values for water depths perpendicular to the ship's long axis. The accuracy of the measurement is approx. 1% of water depth, the frequency of the acoustic signal is 15.5 kHz. The refraction of the sonar beams was corrected by automatic crossfan calibration. By regular transmission and measurement of a sweep profile in the ship's longitudinal direction and comparison of the slant beams with the vertical beam, the mean sound velocity over the vertical water column is determined and is used for the depth computation. The data collected include depth, sidescan (2048 values per scan), and backscatter information on each of the 59 beams. During this cruise, the Lena Trough was surveyed systematically for the first time by a multibeam sonar system. The recorded area has an expanse of approx. 100000 km2 and connects previously mapped areas of the Eurasian - North-American plate boundary between Fram Strait and Gakkel Ridge. The region of Western Gakkel Ridge, mapped in 2001 (AMOR-Expedition) by RV Polarstern and USCGC Healy (USA), was extended by two more profiles (each 220 km long) along the ridge. In order to produce working maps for the expedition, the multibeam sonar data were gridded with a spacing of 50 m, producing plots with various contour line intervals. For further morphological interpretation of Lena Trough and Gakkel Ridge slope magnitude maps, slope direction maps and

  13. [Comparative analysis of two diffusion methods for radon Rn-222 estimation in atmospheric air by means of gamma ray spectrometry and liquid scintillation counting].

    Science.gov (United States)

    Gorzkowski, B; Pachocki, K; Peńsko, J; Majle, T; Rózycki, Z

    1995-01-01

    The comparative measurements of radon Rn-222 concentration in indoor air of some buildings and in radon labour chamber have been conducted using two different diffusions methods. The results of parallel measurements using radon charcoal detectors and gamma-rays spectrometry with liquid alpha scintillation counting (Pico-Rad) have been presented. It was concluded that both methods offer the similar measurements possibilities of radon concentrations in the air from about 30 Bq/m3 to about 600 Bq/m3 with the real average divergence between both methods of about +/- 11%.

  14. Extraits de Pobeg kumaniki / La Pousse de mûrier sauvage de Lena Eltang

    Directory of Open Access Journals (Sweden)

    Lena Eltang

    2012-06-01

    Full Text Available PrésentationLena Eltang (1964, Leningrad, journaliste et traductrice, s’est fait connaître en tant que poète dès 2003 grâce à la parution de ses recueils de poèmes Jantarnyj skaz (La légende d’ambre, 2003 et Drugie vozmožnosti (Autres possibilités, 2004. Son premier roman, Pobeg kumaniki (La pousse de mûrier sauvage, 2006 nous plonge dans une aventure mystico-ésotérique, où un historien, Oscar Theo Forge, est persuadé d’avoir retrouvé six artéfacts indispensables au Grand œuvre lors de fo...

  15. Status of the Inclusive νμ CC Cross Section Measurement in the NOvA Near Detector

    Science.gov (United States)

    Behera, Biswaranjan

    2017-01-01

    NOvA is a long-baseline (810 km) neutrino oscillation experiment. It uses the NuMI neutrino beam from Fermilab and two mostly active, segmented, liquid scintillator off-axis detectors that offer a remarkable capability in event identification. One of the main purposes of the 293 ton Near Detector at Fermilab is to measure the unoscillated neutrino energy spectrum, which can be used to predict the neutrino energy spectrum at the 14 kton Far Detector at Ash River, MN. In addition to that, it also provides an excellent opportunity to measure cross sections with high statistics. Improved understanding of neutrino-nucleus interactions will benefit current and future long-baseline neutrino oscillation experiments. In this talk we present the status of the measurement of the inclusive νμ charge current cross section in the NOvA Near Detector.

  16. Combination of chemical separation and data treatment for {sup 55}Fe, {sup 63}Ni, {sup 99}Tc, {sup 137}Cs and {sup 90}Sr/{sup 90}Y activity determination in radioactive waste by liquid scintillation

    Energy Technology Data Exchange (ETDEWEB)

    Mellado, J. [Departament de Quimica Analitica, Facultat de Quimica, Universitat de Barcelona, C/Marti Franques 1, 08028 Barcelona (Spain); Tarancon, A. [Departament de Quimica Analitica, Facultat de Quimica, Universitat de Barcelona, C/Marti Franques 1, 08028 Barcelona (Spain); Garcia, J.F. [Departament de Pintura, Facultat de Belles Arts, Universitat de Barcelona, C/Pau Gargallo 4, 08028 Barcelona (Spain)]. E-mail: jfgarcia@apolo.qui.ub.es; Rauret, G. [Departament de Quimica Analitica, Facultat de Quimica, Universitat de Barcelona, C/Marti Franques 1, 08028 Barcelona (Spain); Warwick, P. [Geoscience Advisory Unit, Southampton Oceanography Centre, Southampton SO14 3ZH (United Kingdom)

    2005-08-01

    Routine operations involving nuclear reactors and decommissioning activities require numerous chemical analyses. Most of the procedures developed for these chemical characterisations involve several separation steps to prepare the sample for measurement. Chemical treatments are time- and manpower-consuming, labour intensive and produce significant quantities of waste. In order to address this problem, we evaluate a data treatment procedure (multivariate calibration-PLS), which we propose as a substitute to some of these separation steps. Mixtures of beta emitter radionuclides of increasing complexity ({sup 90}Sr/{sup 90}Y-{sup 99}Tc, {sup 90}Sr/{sup 90}Y-{sup 99}Tc-{sup 63}Ni-{sup 137}Cs and {sup 90}Sr/{sup 90}Y-{sup 99}Tc-{sup 63}Ni-{sup 137}Cs-{sup 55}Fe) have been measured by liquid scintillation (LS) counting. The influences of quenching and level of activity was evaluated and the activity of unknown samples determined. Despite the spectra overlapping and low resolution of LS, relative errors in the activities quantification of unknown samples inside the range covered by the calibration matrix are lower than 15% whatever the number of radionuclides included in the solution was.

  17. Determination of total alpha and beta activity in water for human consumption by LSC(Liquid Scintillation Counter); Determinacao de atividades alfa e beta total em agua para consumo humano por LSC (Contador de Cintilacao Liquida))

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    The Ordinance Brazilian of Ministry of Health (MS 2914/2011) establishes the standards for quality of water intended for human consumption, being limits values of 5.0 Bq/L for gross alpha, and 1.0 Bq/L for gross beta radioactivity. The liquid scintillation spectrometry (LSC) technique has been presented as an alternative to conventional procedure using gas flow proportional counter. The present work shows a review of the methods for determination of gross alpha and gross beta in water by using LSC. Between the factors that influence the accuracy and repeatability of the analytical results we can highlight: thermal preconcentration, type of the acid and calibration standard. A procedure was established and carried out to samples of the National Program of Intercomparison of Radionuclides in Environmental Samples for evaluation of its performance. The gross alpha and gross beta analysis in samples of the public water supplies in the Metropolitan Region of Goiania, state of Goias was carried out. The results are consistent with the guideline values form the Ministry of Health concerning radioactivity. (author)

  18. Research on the Progeny Volume Activity Measuring Method of 222 Rn with Liquid Scintillation Counting%氡子体体积活度的液体闪烁计数方法研究

    Institute of Scientific and Technical Information of China (English)

    杨志杰; 李则书; 侯胜利; 刘皓然; 张明; 梁珺成

    2015-01-01

    Based on liquid scintillation counting,a measuring method of 222 Rn progeny volume activity is established. Using this kind of method,measurements are executed in NIM’s radon chamber when 222 Rn and its progenies get to the secure equilibrium,and a typically expanded uncertainty of 1. 5%(k = 2)for the potential alpha energy concentration is obtained. Comparative measurements based on the alpha energy spectrum are also executed and the results of the two methods agree within the estimated uncertainty limit.%基于液体闪烁计数原理和滤膜采样技术,建立了一种氡(222 Rn)子体体积活度和α潜能浓度的测量方法。应用该方法对氡室中处于放射性平衡状态的氡子体体积活度进行了取样测量,氡子体α潜能浓度测量结果的扩展不确定度小于1.5%(k =2);用α能谱法对氡子体液体闪烁计数测量方法进行了旁证,两种方法的测量结果在不确定度范围内一致。

  19. Seminar on Detectors and measurements techniques

    Energy Technology Data Exchange (ETDEWEB)

    Holm, E. (ed.) [Risoe National Lab., Roskilde (Denmark)

    2002-07-01

    A Nordic Seminar on detectors and radionuclide measurement techniques was held in Lund, Sweden, May 3-4, 2001. The objective was to highlight recent progress and problems for techniques to study environmental radioactivity. It covered the aspect of detector sample geometry's and methods for evaluation of gamma gamma pulse height distributions. Within the field of alpha-spectrometric techniques gridded ionisation chambers, semiconductor detectors and a general description for analysis of alpha-particle-spectra were presented. Recent development in mass spectrometric techniques, AMS (Accelerator Mass Spectrometry) and ICPMS (Inductively Coupled Plasma mass Spectrometry) for long-lived radionuclides was described. Principles for analysis of beta particle emitters, especially by liquid scintillation were presented. The seminar also covered radiochemistry such advantages and disadvantages between ion exchange, solvent extraction and extraction chromatography. The use of controlled laboratory conditions for discerning the dynamics of accumulation in organisms was demonstrated. Other techniques such as neutron activation were also shown to be useful analytical tool for certain long-lived radionuclides. The results of the intercalibration exercises within the Nordic countries showed the importance of such analytical quality control. (au)

  20. Digital Acquisition Development for Fast Neutron Detectors

    Science.gov (United States)

    Seagren, T.; Mosby, S.; Mona Collaboration; Lansce P-27 Team

    2015-10-01

    The use of the Modular Neutron Array (MoNA) at FRIB requires a thorough understanding of how neutrons propagate through the array. This leads to the increasing importance of accuracy in detector response simulations, particularly in the case of FRIB's higher beam energies. An upcoming experiment at the LANSCE facility at Los Alamos National Lab will benchmark neutron propagation through the MoNA array and provide a more complete validation of the simulation software. LANSCE also hosts the Chi-Nu experiment, which seeks to measure fission output neutrons using the high-intensity neutron beams there. In both experiments, the instantaneous rate on the detectors involved is expected to be very high, due to the LANSCE/WNR beam structure. Therefore, waveform digitizers with on-board processing are required in order for the experiments to succeed. These digitizers provide on-board timing algorithms using FPGA firmware, and several tests were preformed in order to determine what the optimal timing filter settings were for a variety of detectors, including the plastic and liquid scintillators to be used in MoNA and Chi-Nu respectively. This work will inform the execution of the MoNA and Chi-Nu experiments at LANSCE. The details of the methods used and results will be presented. Supported by funding through Los Alamos National Lab and NSF Grant PHY-1506402.

  1. pp-Solar Neutrino Spectroscopy Return of the Indium Detector

    CERN Document Server

    Raghavan, R S

    2001-01-01

    A new indium-loaded liquid scintillator (LS) with up to 15wt% In and high light output promises a breakthrough in the 25y old proposal for observing pp solar neutrinos (nue) by tagged nue capture in 115In. Intense background from the natural beta-decay of In, the single obstacle blocking this project till now, can be reduced by more than x100 with the new In-LS. Only non-In background remains, dramatically relaxing design criteria. Eight tons of In yields ~400 pp nue/y after analysis cuts. With the lowest threshold yet, Q=118 keV, In is the most sensitive detector of the pp nue spectrum, the long sought touchstone for nue conversion.

  2. Fast Muon Simulation in the JUNO Central Detector

    CERN Document Server

    Lin, Tao; Li, Weidong; Cao, Guofu; You, Zhengyun; Li, Xinying

    2016-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment designed to measure the neutrino mass hierarchy using a central detector (CD), which contains 20 kton liquid scintillator (LS) surrounded by about 17,000 photomultiplier tubes (PMTs). Due to the large fiducial volume and huge number of PMTs, the simulation of a muon particle passing through the CD with the Geant4 toolkit becomes an extremely computation-intensive task. This paper presents a fast simulation implementation using a so-called voxel method: for scintillation photons generated in a certain LS voxel, the PMT's response is produced beforehand with Geant4 and then introduced into the simulation at runtime. This parameterisation method successfully speeds up the most CPU consuming process, the optical photon's propagation in the LS, by a factor of 50. In the paper, the comparison of physics performance between fast and full simulation is also given.

  3. Measurement of the response function and the detection efficiency of an organic liquid scintillator for neutrons between 1 and 30 MeV

    Institute of Scientific and Technical Information of China (English)

    HUANG Han-Xiong; RUAN Xi-Chao; CHEN Guo-Chang; ZHOU Zu-Ying; LI Xia; BAO Jie; NIE Yang-Bo; ZHONG Qi-Ping

    2009-01-01

    The light output function of a φ50.8 mm×50.8 mm BC501A scintillation detector was measured in the neutron energy region of 1 to 30 MeV by fitting the pulse height (PH) spectra for neutrons with the simulations from the NRESP code at the edge range. Using the new light output function, the neutron detection efficiency was determined with two Monte-Carlo codes, NEFF and SCINFUL. The calculated efficiency was corrected by comparing the simulated PH spectra with the measured ones. The determined efficiency was verified at the near threshold region and normalized with a Proton-Recoil-Telescope (PRT) at the 8-14 MeV energy region.

  4. Neutron spectroscopy with scintillation detectors using wavelets

    Science.gov (United States)

    Hartman, Jessica

    The purpose of this research was to study neutron spectroscopy using the EJ-299-33A plastic scintillator. This scintillator material provided a novel means of detection for fast neutrons, without the disadvantages of traditional liquid scintillation materials. EJ-299-33A provided a more durable option to these materials, making it less likely to be damaged during handling. Unlike liquid scintillators, this plastic scintillator was manufactured from a non-toxic material, making it safer to use, as well as easier to design detectors. The material was also manufactured with inherent pulse shape discrimination abilities, making it suitable for use in neutron detection. The neutron spectral unfolding technique was developed in two stages. Initial detector response function modeling was carried out through the use of the MCNPX Monte Carlo code. The response functions were developed for a monoenergetic neutron flux. Wavelets were then applied to smooth the response function. The spectral unfolding technique was applied through polynomial fitting and optimization techniques in MATLAB. Verification of the unfolding technique was carried out through the use of experimentally determined response functions. These were measured on the neutron source based on the Van de Graff accelerator at the University of Kentucky. This machine provided a range of monoenergetic neutron beams between 0.1 MeV and 24 MeV, making it possible to measure the set of response functions of the EJ-299-33A plastic scintillator detector to neutrons of specific energies. The response of a plutonium-beryllium (PuBe) source was measured using the source available at the University of Nevada, Las Vegas. The neutron spectrum reconstruction was carried out using the experimentally measured response functions. Experimental data was collected in the list mode of the waveform digitizer. Post processing of this data focused on the pulse shape discrimination analysis of the recorded response functions to remove the

  5. Development of detector for neutron monitor of wide energy range. Joint research

    CERN Document Server

    Kim, E; Nakamura, T; Rasolonjatovo, D R D; Shiomi, T; Tanaka, S; Yamaguchi, Y; Yoshizawa, M

    2002-01-01

    Radiation monitoring of neutrons in high-power proton accelerator facilities is very important for radiation safety management for workers and members of the public. In the present study, a neutron detector that can evaluate dose of neutrons in the energy range from thermal energy to 100MeV was developed using an organic liquid scintillator, a boron-loaded scintillator and a sup 6 Li glass scintillator. First, a method was developed to evaluate neutron doses above several MeV by a spectrum weight function (G-function) which is applied to the organic liquid scintillator, and the validity of the methods was confirmed by dose evaluation in some neutron fields. Second, the G-function was applied to the boron-loaded scintillator which detects thermal neutrons by sup 1 sup 0 B(n, alpha) sup 7 Li reaction, in order to expand the covering neutron energy range. The response function and the G-function of the scintillator were evaluated by experiment and calculation, and the characteristics of dose measurement were ana...

  6. Extensive Air Shower Detector Array at the Universidad Autonoma de Puebla

    Science.gov (United States)

    Cotzomi, J.; Moreno, E.; Aguilar, S.; Palma, B.; Martinez, O.; Salazar, H.; Villasenor, L.

    2002-07-01

    We describe the operation of an Extensive Air Shower Array located at the campus of the FCFM-BUAP. The array consists of 8 liquid scintillation detectors with a surface of 1 m2 each and a detector spacing of 20 m in a square grid. The array was designed to measure the energy and arrival direction of primary particles that generate extensive air showers (EAS) in the region of 1013 eV - 1016 eV. The angular distribution measured with this array, Cos8(Theta) xSin(Theta), agrees very well with the literature. We also present the measured energies of a number of vertical showers in the range of 5 x1012 eV to 5 x1013 eV.

  7. Assessing Silicate Weathering in Permafrost-Dominated Catchments Using Lithium Isotopes: The Lena River, Siberia

    Science.gov (United States)

    Murphy, M. J.; Pogge von Strandmann, P.; Porcelli, D.; Katchinoff, J. A.; Moreras Martí, A.; Hirst, C. A.; Andersson, P. S.; Maximov, T. C.

    2015-12-01

    Rising global temperatures have the potential to influence the Earth's climate feedback cycles due to permafrost thawing, altering the freshwater input and trace metal and carbon fluxes into the ocean and atmosphere. Riverine lithium isotope ratios (d7Li) are a tracer of silicate weathering processes, which are key in the removal of atmospheric CO2 over geological timescales. Despite this, little is known about the effects of permafrost thawing on d7Li variations. Strong seasonal changes in the thawed active layer thickness dictate surficial water flow paths, which may influence intra-annual riverine d7Li signatures. We present a study of the dissolved d7Li from the large permafrost-dominated watersheds of the Lena River (Siberia), which drain into the Arctic Ocean. This work comprises a temporal study during the May 2015 spring flood, from ice breakup through peak flooding, thus monitoring changes in water-rock and water-soil interaction, both processes that control weathering and hence Li isotopes. Before riverine ice started to break up, high [Li] are observed as the river signature is governed by winter base flow conditions. As the river ice breaks up, surface runoff flows over the impermeable permafrost, interacting with leaf litter, diluting the [Li]. We compare d7Li over the spring flood period with a greater spatial study conducted over two summer field seasons (2012/2013) of the main Lena River channel and its tributaries, which drain a variety of lithologies/topographies. During the summer, the thawed active layer promotes deeper water flow paths, greater water-rock interaction and enhanced secondary minerals formation which preferentially take up 6Li. Summer riverine d7Li typically fall between +14.5 ‰ to +28.5 ‰, with rivers draining the Central Siberian Plateau typically exhibiting high [Li], but similar δ7Li to rivers draining the Verkhoyansk Mountain Range. Overall, this study demonstrates how Li isotopes respond to weathering in a permafrost

  8. Fast ion energy distribution from third harmonic radio frequency heating measured with a single crystal diamond detector at the Joint European Torus

    Energy Technology Data Exchange (ETDEWEB)

    Nocente, M.; Rebai, M.; Gorini, G. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Dipartimento di Fisica “G. Occhialini,” Università degli Studi di Milano-Bicocca, Milano (Italy); Istituto di Fisica del Plasma “P. Caldirola,” Consiglio Nazionale delle Ricerche, Milano (Italy); Cazzaniga, C. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Istituto di Fisica del Plasma “P. Caldirola,” Consiglio Nazionale delle Ricerche, Milano (Italy); Rutherford Appleton Laboratory, ISIS Facility, Didcot (United Kingdom); Tardocchi, M.; Giacomelli, L.; Muraro, A. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Istituto di Fisica del Plasma “P. Caldirola,” Consiglio Nazionale delle Ricerche, Milano (Italy); Binda, F.; Eriksson, J. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Sharapov, S. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Collaboration: (EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)

    2015-10-15

    Neutron spectroscopy measurements with a single crystal diamond detector have been carried out at JET, for the first time in an experiment aimed at accelerating deuterons to MeV energies with radio frequency heating at the third harmonic. Data are interpreted by means of the expected response function of the detector and are used to extract parameters of the highly non-Maxwellian distribution function generated in this scenario. A comparison with observations using a time of flight and liquid scintillator neutron spectrometers is also presented. The results demonstrate the capability of diamond detectors to contribute to fast ion physics studies at JET and are of more general relevance in view of the application of such detectors for spectroscopy measurements in the neutron camera of next step tokamak devices.

  9. Fast ion energy distribution from third harmonic radio frequency heating measured with a single crystal diamond detector at the Joint European Torus.

    Science.gov (United States)

    Nocente, M; Cazzaniga, C; Tardocchi, M; Binda, F; Eriksson, J; Giacomelli, L; Muraro, A; Rebai, M; Sharapov, S; Gorini, G

    2015-10-01

    Neutron spectroscopy measurements with a single crystal diamond detector have been carried out at JET, for the first time in an experiment aimed at accelerating deuterons to MeV energies with radio frequency heating at the third harmonic. Data are interpreted by means of the expected response function of the detector and are used to extract parameters of the highly non-Maxwellian distribution function generated in this scenario. A comparison with observations using a time of flight and liquid scintillator neutron spectrometers is also presented. The results demonstrate the capability of diamond detectors to contribute to fast ion physics studies at JET and are of more general relevance in view of the application of such detectors for spectroscopy measurements in the neutron camera of next step tokamak devices.

  10. Proof of principle of a high-spatial-resolution, resonant-response gamma-ray detector for Gamma Resonance Absorption in 14N

    CERN Document Server

    Brandis, M; Vartsky, D; Friedman, E; Kreslo, I; Mardor, I; Dangendorf, V; Levi, S; Mor, I; Bar, D

    2011-01-01

    The development of a mm-spatial-resolution, resonant-response detector based on a micrometric glass capillary array filled with liquid scintillator is described. This detector was developed for Gamma Resonance Absorption (GRA) in 14N. GRA is an automatic-decision radiographic screening technique that combines high radiation penetration (the probe is a 9.17 MeV gamma ray) with very good sensitivity and specificity to nitrogenous explosives. Detailed simulation of the detector response to electrons and protons generated by the 9.17 MeV gamma-rays was followed by a proof-of-principle experiment, using a mixed gamma-ray and neutron source. Towards this, a prototype capillary detector was assembled, including the associated filling and readout systems. Simulations and experimental results indeed show that proton tracks are distinguishable from electron tracks at relevant energies, on the basis of a criterion that combines track length and light intensity per unit length.

  11. Proof of principle of a high-spatial-resolution, resonant-response γ-ray detector for Gamma Resonance Absorption in 14N

    Science.gov (United States)

    Brandis, M.; Goldberg, M. B.; Vartsky, D.; Friedman, E.; Kreslo, I.; Mardor, I.; Dangendorf, V.; Levi, S.; Mor, I.; Bar, D.

    2011-02-01

    The development of a mm-spatial-resolution, resonant-response detector based on a micrometric glass capillary array filled with liquid scintillator is described. This detector was developed for Gamma Resonance Absorption (GRA) in 14N. GRA is an automatic-decision radiographic screening technique that combines high radiation penetration (the probe is a 9.17 MeV γ-ray) with very good sensitivity and specificity to nitrogenous explosives. Detailed simulation of the detector response to electrons and protons generated by the 9.17 MeV γ-rays was followed by a proof-of-principle experiment, using a mixed γ-ray and neutron source. Towards this, a prototype capillary detector was assembled, including the associated filling and readout systems. Simulations and experimental results indeed show that proton tracks are distinguishable from electron tracks at relevant energies, based on a criterion that combines track length and light intensity per unit length.

  12. Microdosimetric measurements in the thermal neutron irradiation facility of LENA reactor.

    Science.gov (United States)

    Colautti, P; Moro, D; Chiriotti, S; Conte, V; Evangelista, L; Altieri, S; Bortolussi, S; Protti, N; Postuma, I

    2014-06-01

    A twin TEPC with electric-field guard tubes has been constructed to be used to characterize the BNCT field of the irradiation facility of LENA reactor. One of the two mini TEPC was doped with 50ppm of (10)B in order to simulate the BNC events occurring in BNCT. By properly processing the two microdosimetric spectra, the gamma, neutron and BNC spectral components can be derived with good precision (~6%). However, direct measurements of (10)B in some doped plastic samples, which were used for constructing the cathode walls, point out the scarce accuracy of the nominal (10)B concentration value. The influence of the Boral(®) door, which closes the irradiation channel, has been measured. The gamma dose increases significantly (+51%) when the Boral(®) door is closed. The crypt-cell-regeneration weighting function has been used to measure the quality, namely the RBEµ value, of the radiation field in different conditions. The measured RBEµ values are only partially consistent with the RBE values of other BNCT facilities.

  13. Estimation of Continental-Basin-Scale Sublimation in the Lena River Basin, Siberia

    Directory of Open Access Journals (Sweden)

    Kazuyoshi Suzuki

    2015-01-01

    Full Text Available The Lena River basin in Siberia produces one of the largest river inflows into the Arctic Ocean. One of the most important sources of runoff to the river is spring snowmelt and therefore snow ablation processes have great importance for this basin. In this study, we simulated these processes with fine resolution at basin scale using MicroMet/SnowModel and SnowAssim. To assimilate snow water equivalent (SWE data in SnowAssim, we used routine daily snow depth data and Sturm’s method. Following the verification of this method for SWE estimation in the basin, we evaluated the impact of snow data assimilation on basin-scale snow ablation. Through validation against MODIS snow coverage data and in situ snow survey observations, we found that SnowAssim could not improve on the original simulation by MicroMet/SnowModel because of estimation errors within the SWE data. Vegetation and accumulated snowfall control the spatial distribution of sublimation and we established that sublimation has an important effect on snow ablation. We found that the ratio of sublimation to snowfall in forests was around 26% and that interannual variation of sublimation modulated spring river runoff.

  14. Organic matter composition and stabilization in a polygonal tundra soil of the Lena Delta

    Directory of Open Access Journals (Sweden)

    S. Höfle

    2013-05-01

    Full Text Available This study investigated soil organic matter (OM composition of differently stabilized soil OM fractions in the active layer of a polygonal tundra soil in the Lena Delta, Russia, by applying density and particle size fractionation combined with qualitative OM analysis using solid state 13C nuclear magnetic resonance spectroscopy, and lipid analysis combined with 14C analysis. Bulk soil OM was mainly composed of plant-derived, little-decomposed material with surprisingly high and strongly increasing apparent 14C ages with active layer depth suggesting slow microbial OM transformation in cold climate. Most soil organic carbon was stored in clay and fine-silt fractions (n-alkane and n-fatty acid compounds and low alkyl/O-alkyl C ratios. Organo-mineral associations, which are suggested to be a key mechanism of OM stabilization in temperate soils, seem to be less important in the active layer as the mainly plant-derived clay- and fine-silt-sized OM was surprisingly "young", with 14C contents similar to the bulk soil values. Furthermore, these fractions contained less organic carbon compared to density fractionated OM occluded in soil aggregates – a further important OM stabilization mechanism in temperate soils restricting accessibility of microorganisms. This process seems to be important at greater active layer depth where particulate OM, occluded in soil aggregates, was "older" than free particulate OM.

  15. Variations of hydrological characteristics at the rivers of different size in the Lena river basin

    Science.gov (United States)

    Semenova, Olga; Tananaev, Nikita; Lebedeva, Luidmila; Popova, Evdokiya

    2016-04-01

    There are many speculations about possible impact of climate change at hydrological regime of Northern Eurasia, and permafrost basins in particular. Though the changes of flow of large rivers are relatively well described, the trends for small and middle-size watersheds are unknown. After the papers by Shiklomanov et al. (2007) and Smith et al. (2007) examining the variations of maximum and minimum flow in Northern Russia by 2001 there was no much update in this issue. In this study we compiled the database of continuous daily runoff for about 110 gauges within the Lena River basin with the order of basin area from 10 to 100000 sq.km. All currently functioning flow gauges with continuous observations not less than 35 years were selected for the database which contains the data up to 2013. For chosen gauges the parameters of row-correlation, cyclic recurrence and the stationarity of main runoff characteristics (mean, maximum and minimum flow) were estimated. The conclusions are drawn about the evidence of unsteadiness and/or internal correlation in runoff series; the robust indicators of the intensity of detected changes are evaluated; the duration of water cycles and evaluation the spatial correlation between water cycles are explored. The study is supported by Russian Foundation for Basic Research (project 15-35-21146 mol_a).

  16. Calibration of radionuclides with decay trough beta emission or electron capture by liquid scintillation technique; Calibracao de radionuclideos que decaem por emissao beta ou por captura eletronica pela tecnica de cintilacao liquida

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Jamir dos Santos

    2000-02-01

    In this work is reported a methodology a methodology for pure beta and electron capture radionuclides standardization, suing liquid scintillation technique. In this sense the CIEMAT/NIST method, recently utilized by international laboratories, was implemented and the lack in the Laboratorio Nacional das Radiacoes Ionizantes - LNMRI, of the Comissao Nacional de Energia Nuclear - CNEN, for adequate methodology to standardize this kind if radionuclides was filled, fact that was not present with alpha and gamma radionuclides. The implementation procedure evaluation was provided by concentration activity determination of the following radionuclides: {sup 14} C and {sup 90} Sr, pure beta emitters; {sup 55} Fe, electron capture decay; {sup 204} Tl, electron capture and beta decay and {sup 60} Co, beta-gamma emitter. In this way, a careful analysis of the implementation procedure with these radionuclides types, ranging on a broad energy spectral, was possible. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. Besides this intercomparisons, one was provided with a {sup 204} Tl solution, utilized in the international comparison recently promoted by BIPM, and another one with a {sup 60} C solution calibrated in LNMRI/CNEN previously by a relative calibration system, with a well type pressurized ionization chamber, and an absolute beta-gamma coincidence system, with a pill-box type proportional counter 4 {pi} geometry, coupled with a scintillator system with a sodium iodide cristal of 4x4 inches. The comparisons among LNMRI/CNEN results and the reference values, showed a small deviation of 1,32% for {sup 14} C, 0,40% for {sup 60} Co, 1,12% for {sup 55} Fe, 0,10% for {sup 90} Sr and 0,73% for {sup

  17. Cryosols of the Northeast Siberian Lena River Delta and its hinterland - genesis and diversity

    Science.gov (United States)

    Zubrzycki, Sebastian; Kutzbach, Lars; Pfeiffer, Eva-Maria

    2016-04-01

    The North-Siberian Lena River Delta (LRD) is the largest Arctic delta and an important interface between the Arctic Ocean in the North and the large Siberian land masses in the South. LRD consists not only of Holocene deltaic sediment deposits as a river terrace and the modern active floodplains but also of remnants of the former Pleistocene mainland including large islands of ice-complex sediments and the Arga-Muora-Sise Island, which is composed of pure sand sediments of still debated origin. The highly diverse landscape structure of LRD is reflected by a great variety of permafrost-affected soils (cryosols). This study aims at describing this great cryosol diversity and at analysing the dominant soil-forming processes in this comparatively scarcely studied soil region. The soil development in the investigated continuous permafrost region is limited by the short thawing period of around three months (June to September) and takes place in the shallow (below 1 m) seasonally thawed active layer. The geological parent material plays an important role for the development of soils in the LRD region. The distribution of the various soil types closely follows the pattern of the geomorphic units characterised by differing sedimentation conditions. The properties and genesis of the soils on the Holocene river terrace and the modern floodplains are strongly affected by the enormous amounts of fluvial sediments (about 12 x 106 tons per year) brought by the Lena River into its delta. The fluvial sedimentation together with the also pronounced aeolian sedimentation results in a fast vertical growth of soils. The upward rise of the soil surface leads to an upward movement of the permafrost table resulting in fast incorporation of soil material formed in the supra-permafrost zone into the permafrost. Due to the morphodynamics of ice-wedge polygons and resulting formation of patterned ground with elevated rims and depressed and water-saturated centres, the Holocene river terrace

  18. Magnetic Susceptibility Signals to Reconstruct Lena River Freshwater Discharge Events in the Laptev Sea and Neelov Bay, Russian Arctic.

    Science.gov (United States)

    Rivera, J.; Williams, D. F.; Karabanov, E. B.; Kuzmin, M.; Buchinskyi, V.

    2004-12-01

    River discharge into the Arctic is known to cause changes in sea ice production and consecutively affect global climate. The Russian Lena River is one of the major contributors into the Arctic Ocean, delivering approximately 770 km3/year of freshwater and about 21 x106/year tons of suspended material. Here we present preliminary evidence of fresh water discharge events from the Lena River into the Laptev Sea, Russian Arctic. During two separate coring-oceanographic expeditions in July and September, 2003, over 25 piston, gravity and vibro cores were collected from Neelov Bay and along a transect that extends from the delta floodplain onto the Laptev shelf. Preliminary results from our cores demonstrate that high magnetic susceptibility signals are a good indicator of river sediments deposition and provide an estimate of the number and magnitude of the river discharge. Sedigraph analyses in combination with Wet Sieving analysis (grain size > 3phi) reveal changes in grain size distributions and accurate grain size compositions along the core, which are well correlated with high magnetic susceptibility peaks. Based on lithostratigraphic interpretations and magnetic susceptibility correlations, at least 6 major sections are identified as possible discharge events in two transects that extends from the Lena River Delta into the Laptev Sea Shelf. The magnitude of the magnetic susceptibility peaks appears to reflect the strength of flow and the resulting spatial distribution of sediments during each deposition event associated with each unit. In Neelov Bay, cores in Transect 2 show the possibility that terrestrial material may be from a different source than Bykovskaya channel in the south-east part of the bay. This terrestrial material may be transported from coastal sources by wave refraction or by wind, and/or submarine currents. Future work will help us to understand and reconstruct the chronology of observed sedimentological events.

  19. Organic matter composition and stabilization in a polygonal tundra soil of the Lena-Delta

    Directory of Open Access Journals (Sweden)

    S. Höfle

    2012-09-01

    Full Text Available This study investigated soil organic matter (OM composition of differently stabilized soil OM fractions in the active layer of a polygonal tundra soil in the Lena-Delta, Russia by applying density and particle-size fractionation combined with qualitative OM analysis using solid state 13C nuclear magnetic resonance spectroscopy, and lipid analysis combined with 14C analysis. Bulk soil OM was mainly composed of plant-derived, little decomposed material with surprisingly low and strongly increasing apparent 14C ages with active layer depth suggesting slow microbial OM transformation in cold climate. Most soil organic carbon was stored in clay and fine silt fractions (< 6.3 μm, which were composed of little decomposed plant material indicated by the dominance of long n-alkane and n-fatty acid compounds and low alkyl/O-alkyl C ratios. Organo-mineral associations, which are suggested to be a key mechanism of OM stabilization in temperate soils, seem to be less important in the active layer as the mainly plant-derived clay and fine silt sized OM was surprisingly "young" with 14C contents similar to the bulk soil values. Furthermore these fractions contained less organic carbon compared to density fractionated OM occluded in soil aggregates – a further important OM stabilization mechanism in temperate soils restricting accessibility of microorganisms. This process seems to be important at greater active layer depth where particulate OM, occluded in soil aggregates, was "older" than free particulate OM.

  20. Mass Flux of Water, Sediments and Chemical Constituents to the Laptev Sea of the Russian Arctic via the Lena River

    Science.gov (United States)

    Armstrong, S. J.; Karabonov, E. B.; Styles, R.; Buchinskyi, V.; Williams, D. F.; Kuzmin, M. I.

    2004-12-01

    The Lena River, one of the world's longest rivers, stretches from southern Siberia, north of Lake Baikal and is the second largest river contributing to the freshwater budget of the Arctic Ocean. During the summer of 2003, ADCP transects of the river's currents, bathymetry and acoustic backscatter were repeated for 500km reaches and at each major tributary, covering over 3,600km of the river's length. Concurrently, multi-parameter CTD casts, water chemistry and sediment concentrations were sampled. Preliminary results show water flow through the river increased with distance from the headwaters (150m3/s) and increased greatly with contributions from the many tributaries along the river's length, reaching a peak (over 37,000m3/s) 64km before the delta at Stolb. Approximately 94% of the Lena's discharge through the delta was accounted for using ADCP flow calculations from transects in three primary distributaries through the delta. To determine the influence of tidal pumping at the mouth, the principle navigation distributary (Bykovskaya) was resampled at the interface with the Laptev Sea, (mouth of Neelov Bay, near Tiksi), repeatedly over a 40-hour interval revealing a lunar semidiurnal period amplitude of oscillation in flow of the same order magnitude as the `subtidal' discharge. Well-mixed thermohaline profiles were evident in the ebb discharge, but during flood, the water was thermally stratified. The net flux through the mouth accounted for only 70% of the flow to the upper reaches of the same channel (Bykovskaya). A comparison with a historic record of Lena flow places the 2003 samples in phase and approximately equal to the 60-year average. The high resolution ADCP sampling of the currents and acoustic backscatter throughout the measured cross-sections were repeated two-three times per station. Net isopleths of flux will be constructed based on the average of the repeated ADCP transects. The net isopleths will then be used to extrapolate chemistry and

  1. Landscape controls and vertical variability of soil organic carbon storage in permafrost-affected soils of the Lena River Delta

    DEFF Research Database (Denmark)

    Siewert, Matthias Benjamin; Hugelius, Gustaf; Heim, Birgit

    2016-01-01

    in the permafrost. The major geomorphological units of a subregion of the Lena River Delta were mapped with a land form classification using a data-fusion approach of optical satellite imagery and digital elevation data to upscale SOC storage. Landscape mean SOC storage is estimated to 19.2 ± 2.0 kg C m− 2. Our...... by thermal-degradation, the recent floodplain and bare alluvial sediments store considerably less SOC in descending order....

  2. Monte Carlo aided design of the inner muon veto detectors for the Double Chooz experiment

    Science.gov (United States)

    Dietrich, D.; Greiner, D.; Jochum, J.; Lachenmaier, T.; Röhling, M.; Stokes, L. F. F.

    2012-08-01

    The Double Chooz neutrino experiment aims to measure the last unknown neutrino mixing angle θ13 using two identical detectors positioned at sites both near and far from the reactor cores of the Chooz nuclear power plant. To suppress correlated background induced by cosmic muons in the detectors, they are protected by veto detector systems. One of these systems is the inner muon veto. It is an active liquid scintillator based detector and instrumented with encapsulated photomultiplier tubes. In this paper we describe the Monte Carlo aided design process of the inner muon veto, that resulted in a detector configuration with 78 PMTs yielding an efficiency of 99.978±0.004 % for rejecting muon events and an efficiency of > 98.98% for rejecting correlated events induced by muons. A veto detector of this design is currently used at the far detector site and will be built and incorporated as the muon identification system at the near site of the Double Chooz experiment.

  3. Monte Carlo aided design of the inner muon veto detectors for the Double Chooz experiment

    CERN Document Server

    Dietrich, D; Jochum, J; Lachenmaier, T; Stokes, L F F; Röhling, M

    2012-01-01

    The Double Chooz neutrino experiment aims to measure the last unknown neutrino mixing angle theta_13 using two identical detectors positioned at sites both near and far from the reactor cores of the Chooz nuclear power plant. To suppress correlated background induced by cosmic muons in the detectors, they are protected by veto detector systems. One of these systems is the inner muon veto. It is an active liquid scintillator based detector and instrumented with encapsulated photomultiplier tubes. In this paper we describe the Monte Carlo aided design process of the inner muon veto, that resulted in a detector configuration with 78 PMTs yielding an efficiency of 99.978 +- 0.004% for rejecting muon events and an efficiency of >98.98% for rejecting correlated events induced by muons. A veto detector of this design is currently used at the far detector site and will be built and incorporated as the muon identification system at the near site of the Double Chooz experiment.

  4. The EUROBALL neutron wall - design and performance tests of neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Skeppstedt, O.; Roth, H.A.; Lindstroem, L. [Department of Experimental Physics, Chalmers University of Technology and Goeteborg University, S-41296 Goeteborg (Sweden); Wadsworth, R.; Hibbert, I.; Kelsall, N.; Jenkins, D. [Department of Physics, University of York, Heslington York YO1 5DD (United Kingdom); Grawe, H.; Gorska, M. [GSI, D-64229 Darmstadt (Germany); Moszynski, M.; Sujkowski, Z.; Wolski, D.; Kapusta, M. [Soltan Institute for Nuclear Studies, Department of Nuclear Electronics, PL-05-400 Otwock-Swierk (Poland); Hellstroem, M.; Kalogeropoulos, S.; Oner, D. [Division of Cosmic and Subatomic Physics, Lund University, S-22100 Lund (Sweden); Johnson, A.; Cederkaell, J.; Klamra, W. [Royal Institute of Technology, Physics Department, S-10405 Stockholm (Sweden); Nyberg, J.; Weiszflog, M. [The Svedberg Laboratory, Uppsala University, S-75121 Uppsala (Sweden); Kay, J.; Griffiths, R. [CCLRC Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Garces Narro, J.; Pearson, C. [Physics Department, University of Surrey, Guildford GU2 5XH (United Kingdom); Eberth, J. [IKP Universitaet zu Koeln, D-50937 Koeln (Germany)

    1999-02-01

    The mechanical design of the EUROBALL neutron wall and neutron detectors, and their performance measured with a {sup 246,248}Cm fission source are described. The array consists of 15 pseudohexaconical detector units subdivided into three, 149 mm high, hermetically separated segments and a smaller central pentagonal unit subdivided into five segments. The detectors are filled with Bicron BC501A liquid scintillator. Each section of the hexaconical detectors is viewed by a 130 mm diameter Philips XP4512PA photomultiplier while the sections of pentagonal detectors are viewed by Philips XP4312B PMTs. The tests of n-{gamma} discrimination performed by zero-crossing and time-of-flight methods show a full separation of {gamma}- and neutron events down to 50 keV recoil electron energy. These tests demonstrate the excellent timing properties of the detectors and an average time resolution of 1.56 ns. The factors determining the efficiency of neutron detectors are discussed. The total efficiency for the full array for a symmetric fusion-evaporation reaction is predicted to be 0.30. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. The EUROBALL neutron wall - design and performance tests of neutron detectors

    CERN Document Server

    Skeppstedt, Ö; Lindström, L; Wadsworth, R; Hibbert, I; Kelsall, N; Jenkins, D; Grawe, H; aGórska, M; Moszynski, M; Sujkowski, Z; Wolski, D; Kapusta, M; Hellström, M; Kalogeropoulos, S; Oner, D; Johnson, A; Cederkäll, J; Klamra, W; Nyberg, J; Weiszflog, M; Kay, J; Griffiths, R; Garces-Narro, J; Pearson, C; Eberth, J

    1999-01-01

    The mechanical design of the EUROBALL neutron wall and neutron detectors, and their performance measured with a sup 2 sup 4 sup 6 sup , sup 2 sup 4 sup 8 Cm fission source are described. The array consists of 15 pseudohexaconical detector units subdivided into three, 149 mm high, hermetically separated segments and a smaller central pentagonal unit subdivided into five segments. The detectors are filled with Bicron BC501A liquid scintillator. Each section of the hexaconical detectors is viewed by a 130 mm diameter Philips XP4512PA photomultiplier while the sections of pentagonal detectors are viewed by Philips XP4312B PMTs. The tests of n-gamma discrimination performed by zero-crossing and time-of-flight methods show a full separation of gamma- and neutron events down to 50 keV recoil electron energy. These tests demonstrate the excellent timing properties of the detectors and an average time resolution of 1.56 ns. The factors determining the efficiency of neutron detectors are discussed. The total efficiency...

  6. Scintillating properties of frozen new liquid scintillators

    CERN Document Server

    Britvich, G I; Golovkin, S V; Martellotti, G; Medvedkov, A M; Penso, G; Soloviev, A S; Vasilchenko, V G

    1999-01-01

    The light emission from scintillators which are liquid at room temperature was studied in the interval between $+20$~$^{\\circ}$C and $-120$~$^{\\circ}$C, where the phase transition from liquid to solid takes place. The light yield measured at $-120$~$^{\\circ}$C is about twice as much as that observed at $+20$~$^{\\circ}$C. By cooling the scintillator from $+20$~$^{\\circ}$C to $-120$~$^{\\circ}$C and then heating it from $-120$~$^{\\circ}$C to $+20$~$^{\\circ}$C, the light yield varies in steps at well defined temperatures, which are different for the cooling and heating processes. These hysteresis phenomena appear to be related to the solvent rather than to the dopant. The decay time of scintillation light was measured at $+20$~$^{\\circ}$C and $-120$~$^{\\circ}$C. Whilst at room temperature most of the light is emitted with a decay time of 6--8 ns, at $-120$~$^{\\circ}$C a slower component, with a decay time of 25--35 ns, becomes important.

  7. Uncontained νμ charged-current quasi-elastic events at the NOvA far detector

    Science.gov (United States)

    Sepulveda-Quiroz, Jose; NOvA Collaboration

    2017-01-01

    NOvA is a long-baseline neutrino oscillation experiment that uses an upgraded neutrino beam from Fermilab and two highly active, segmented, liquid scintillator off-axis detectors that offer a remarkable capability in event identification. In its first and second analysis results, NOvA has used only events with an interaction vertex and all secondary particles fully contained in the detectors. I will present studies of the potential sensitivity improvement of the sin2 2θ23 and Δm322 neutrino oscillation parameters from the νμ-disappearance measurement when including uncontained events in the sample. In particular, this study focuses on incorporating νμ charged current quasi-elastic interactions of the type νμ + n -> μ + p where the muon is uncontained but the proton is contained.

  8. Preparation of 45Ca(HDEHP)n and (CaH{sub 1}50{sub 2})2 samples for liquid scintillation counting, compared to 45caCl{sub 2} results; Preparacion de Ca (HDEHP)n y (C{sub 8}H{sub 1}50{sub 2})2 marcados con 45Ca y estudio comparativo con 4 5ca Cl2 en medidas por centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L.; Arcos, J. M. los; Grau Malonda, A.

    1994-07-01

    A procedure for preparation of liquid scintillation counting organic samples of the Di-2-ethylhexyl phosphate calcium complex and the 2-ethylhexanoate calcium salt, labelled with 45Ca, is described. The chemical quench, the counting stability and spectral evolution of both compounds is studied in six scintillators,Toluene-alcohol, Dioxane-naphtalene, Hi safe II, Ultimate-Gold and Instagel, and compared to results obtained from a commercial solution of 4 5CaCl2. (Author) 7 refs.

  9. Novel methodology to examine cognitive and experiential factors in language development: combining eye-tracking and LENA technology.

    Science.gov (United States)

    Odean, Rosalie; Nazareth, Alina; Pruden, Shannon M

    2015-01-01

    Developmental systems theory posits that development cannot be segmented by influences acting in isolation, but should be studied through a scientific lens that highlights the complex interactions between these forces over time (Overton, 2013a). This poses a unique challenge for developmental psychologists studying complex processes like language development. In this paper, we advocate for the combining of highly sophisticated data collection technologies in an effort to move toward a more systemic approach to studying language development. We investigate the efficiency and appropriateness of combining eye-tracking technology and the LENA (Language Environment Analysis) system, an automated language analysis tool, in an effort to explore the relation between language processing in early development, and external dynamic influences like parent and educator language input in the home and school environments. Eye-tracking allows us to study language processing via eye movement analysis; these eye movements have been linked to both conscious and unconscious cognitive processing, and thus provide one means of evaluating cognitive processes underlying language development that does not require the use of subjective parent reports or checklists. The LENA system, on the other hand, provides automated language output that describes a child's language-rich environment. In combination, these technologies provide critical information not only about a child's language processing abilities but also about the complexity of the child's language environment. Thus, when used in conjunction these technologies allow researchers to explore the nature of interacting systems involved in language development.

  10. Novel methodology to examine cognitive and experiential factors in language development: combining eye-tracking and LENA technology

    Science.gov (United States)

    Odean, Rosalie; Nazareth, Alina; Pruden, Shannon M.

    2015-01-01

    Developmental systems theory posits that development cannot be segmented by influences acting in isolation, but should be studied through a scientific lens that highlights the complex interactions between these forces over time (Overton, 2013a). This poses a unique challenge for developmental psychologists studying complex processes like language development. In this paper, we advocate for the combining of highly sophisticated data collection technologies in an effort to move toward a more systemic approach to studying language development. We investigate the efficiency and appropriateness of combining eye-tracking technology and the LENA (Language Environment Analysis) system, an automated language analysis tool, in an effort to explore the relation between language processing in early development, and external dynamic influences like parent and educator language input in the home and school environments. Eye-tracking allows us to study language processing via eye movement analysis; these eye movements have been linked to both conscious and unconscious cognitive processing, and thus provide one means of evaluating cognitive processes underlying language development that does not require the use of subjective parent reports or checklists. The LENA system, on the other hand, provides automated language output that describes a child’s language-rich environment. In combination, these technologies provide critical information not only about a child’s language processing abilities but also about the complexity of the child’s language environment. Thus, when used in conjunction these technologies allow researchers to explore the nature of interacting systems involved in language development. PMID:26379591

  11. The electronics and data acquisition system for the DarkSide-50 veto detectors

    Science.gov (United States)

    Agnes, P.; Agostino, L.; Albuquerque, I. F. M.; Alexander, T.; Alton, A. K.; Arisaka, K.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Bottino, B.; Brigatti, A.; Brodsky, J.; Budano, F.; Bussino, S.; Cadeddu, M.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Carlini, M.; Catalanotti, S.; Cavalcante, P.; Chepurnov, A.; Cocco, A. G.; Covone, G.; Crippa, L.; D'Angelo, D.; D'Incecco, M.; Davini, S.; De Cecco, S.; De Deo, M.; De Vincenzi, M.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, G.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Foster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Giganti, C.; Goretti, A. M.; Granato, F.; Grandi, L.; Gromov, M.; Guan, M.; Guardincerri, Y.; Hackett, B. R.; Herner, K. R.; Hungerford, E. V.; Ianni, Aldo; Ianni, Andrea; James, I.; Jollet, C.; Keeter, K.; Kendziora, C. L.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Li, X.; Lissia, M.; Lombardi, P.; Luitz, S.; Ma, Y.; Machulin, I. N.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Meyers, P. D.; Miletic, T.; Milincic, R.; Montanari, D.; Monte, A.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B. J.; Muratova, V. N.; Musico, P.; Napolitano, J.; Nelson, A.; Odrowski, S.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Pelczar, K.; Pelliccia, N.; Pocar, A.; Pordes, S.; Pugachev, D. A.; Qian, H.; Randle, K.; Ranucci, G.; Razeto, A.; Reinhold, B.; Renshaw, A. L.; Riffard, Q.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, S. D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Sangiorgio, S.; Savarese, C.; Segreto, E.; Semenov, D. A.; Shields, E.; Singh, P. N.; Skorokhvatov, M. D.; Smirnov, O.; Sotnikov, A.; Stanford, C.; Suvorov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Trinchese, P.; Unzhakov, E. V.; Vishneva, A.; Vogelaar, R. B.; Wada, M.; Walker, S.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Wilhelmi, J.; Wojcik, M. M.; Xiang, X.; Xu, J.; Yang, C.; Yoo, J.; Zavatarelli, S.; Zec, A.; Zhong, W.; Zhu, C.; Zuzel, G.

    2016-12-01

    DarkSide-50 is a detector for dark matter candidates in the form of weakly interacting massive particles. It utilizes a liquid argon time projection chamber for the inner main detector, surrounded by a liquid scintillator veto (LSV) and a water Cherenkov veto detector (WCV). The LSV and WCV act as the neutron and cosmogenic muon veto detectors for DarkSide-50. This paper describes the electronics and data acquisition system used for these two detectors. The system is made of a custom built front end electronics and commercial National Instruments high speed digitizers. The front end electronics, the DAQ, and the trigger system have been used to acquire data in the form of zero-suppressed waveform samples from the 110 PMTs of the LSV and the 80 PMTs of the WCV. The veto DAQ system has proven its performance and reliability. This electronics and DAQ system can be scaled and used as it is for the veto of the next generation DarkSide-20k detector.

  12. Determination of {sup 90}Sr, {sup 63}Ni and {sup 55}Fe activities by liquid scintillation counting in the environmental samples close to French nuclear power plants located on Loire and Garonne rivers

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, G.; Mokili, M.B.; Le Roy, C.; Deniau, I. [SUBATECH, IN2P3 (France); Gontier, G.; Boyer, C. [EDF-DPI-DIN-CIDEN (France); Hemidy, P.Y. [EDF-DPN-UNIE-GPRE-IEV (France); Chardon, P. [CNRS/IN2P3 (France)

    2014-07-01

    The protection of the aquatic and terrestrial environment from a wide range of radioactive contaminants released by nuclear industry requires continuous monitoring of radionuclides released into the environment. Specific measurement methods depending of the radionuclide are used to determinate this contribution. A lot of radionuclide can easily be measured at low level by gamma spectrometry, like {sup 137}Cs, {sup 60}Co..., but others like {sup 90}Sr, {sup 63}Ni or {sup 55}Fe require prior specific radiochemical separations. Activity of {sup 90}Sr values in environmental samples are available but only few measurements of {sup 63}Ni and {sup 55}Fe activities have been carried out in samples collected in the environment close to French nuclear power plants located on the Loire and Garonne rivers despite they represent 12% to 24% for {sup 63}Ni activity and <1% for {sup 55}Fe + other minor radionuclides of total activity of their liquid effluent discharges. {sup 90}Sr is not rejected by the liquid effluent discharges of Nuclear Power Plants and can be found in the environmental samples because of thermonuclear test and subsequently after the Chernobyl nuclear power plant accident. Considering the French Nuclear Power Plant located on Loire and Garonne rivers, the determination of {sup 90}Sr, {sup 63}Ni and {sup 55}Fe levels in the environmental samples around French nuclear power plants is carried out to detect the traces of these radionuclides originating from nuclear technology activities. The environment around five French nuclear Power Plants was investigated for 4 years between 2009 and 2014. The radionuclide activities determined by liquid scintillation counting after chemical steps were performed on a large set of various matrix samples likely to be encountered in environmental monitoring as soils, sediments, terrestrial and aquatic bio-indicators. It was found that the mean activity concentration of the most frequently detected was for the radionuclide {sup 90

  13. Gold mineralisation and orogenic metamorphism in the Lena province of Siberia as assessed from Chertovo Koryto and Sukhoi Log deposits

    Directory of Open Access Journals (Sweden)

    Marina A. Yudovskaya

    2016-05-01

    Full Text Available The Chertovo Koryto gold deposit (80 t Au at 1.84 g/t in the Lena world-class province, Siberia, is hosted in a metamorphosed sequence of the Paleoproterozoic Mikhailovsk Formation that comprises the oldest black shale strata of the Baikal-Patom region. The mineralisation is confined to the thrust zone complicated with a conjugate anticline fold, zones of shearing and dislocation. The structural position of the mineralisation is similar to that at the giant Sukhoi Log deposit in the neighbouring Mama-Bodaibo zone. In the latter, the isotope age data suggest that Khomolkho black shales, hosts to Sukhoi Log mineralisation, are of Ediacaran age and underwent prograde metamorphism during early Paleozoic. The geochemical composition of the terrigenous rocks that host Sukhoi Log, Chertovo Koryto, and a number of other deposits at the various stratigraphic levels throughout the Proterozoic sequence have much in common. They do not show elevated metal contents above the common black shale abundances, except for Au and As, which is at variance with the accepted view on diagenetic enrichment of black shales in the Lena province. The occurrence of sagenitic rutile in quartz and chlorite pseudomorphs after biotite and other petrographic observations provide evidence on a retrograde nature of the metamorphic mineral assemblages in the Mikhailovsk rocks. The sulphides are pyrrhotite and arsenopyrite with very minor pyrite at Chertovo Koryto, whereas pyrite is the predominant sulphide in the Sukhoi Log ore. Fluid inclusion data on both deposits emphasise a high-temperature nature of the mineralisation albeit revealing great contrast in the fluid composition. Sukhoi Log mineralisation was formed at mixing between low-salinity aqueous solutions and dense gaseous carbonic fluids, which facilitated effective gold scavenging and precipitation, as demonstrated by thermodynamic simulation. The precursory devolatilisation of the Mikhailovsk sediments at the prograde

  14. Gold mineralisation and orogenic metamorphism in the Lena province of Siberia as assessed from Chertovo Koryto and Sukhoi Log deposits

    Institute of Scientific and Technical Information of China (English)

    Marina A. Yudovskaya; Vadim V. Distler; Vsevolod Yu. Prokofiev; Nickolay N. Akinfiev

    2016-01-01

    The Chertovo Koryto gold deposit (80 t Au at 1.84 g/t) in the Lena world-class province, Siberia, is hosted in a metamorphosed sequence of the Paleoproterozoic Mikhailovsk Formation that comprises the oldest black shale strata of the Baikal-Patom region. The mineralisation is confined to the thrust zone complicated with a conjugate anticline fold, zones of shearing and dislocation. The structural position of the mineralisation is similar to that at the giant Sukhoi Log deposit in the neighbouring Mama-Bodaibo zone. In the latter, the isotope age data suggest that Khomolkho black shales, hosts to Sukhoi Log mineralisation, are of Ediacaran age and underwent prograde metamorphism during early Paleozoic. The geochemical composition of the terrigenous rocks that host Sukhoi Log, Chertovo Koryto, and a number of other deposits at the various stratigraphic levels throughout the Proterozoic sequence have much in common. They do not show elevated metal contents above the common black shale abundances, except for Au and As, which is at variance with the accepted view on diagenetic enrichment of black shales in the Lena province. The occurrence of sagenitic rutile in quartz and chlorite pseudomorphs after biotite and other petrographic observations provide evidence on a retrograde nature of the metamorphic mineral assemblages in the Mikhailovsk rocks. The sulphides are pyrrhotite and arsenopyrite with very minor pyrite at Chertovo Koryto, whereas pyrite is the predominant sulphide in the Sukhoi Log ore. Fluid inclusion data on both deposits emphasise a high-temperature nature of the mineralisation albeit revealing great contrast in the fluid composition. Sukhoi Log mineralisation was formed at mixing be-tween low-salinity aqueous solutions and dense gaseous carbonic fluids, which facilitated effective gold scavenging and precipitation, as demonstrated by thermodynamic simulation. The precursory devola-tilisation of the Mikhailovsk sediments at the prograde stage results in

  15. Trace metal distribution in pristine permafrost-affected soils of the Lena River Delta and its Hinterland, Northern Siberia, Russia

    Directory of Open Access Journals (Sweden)

    I. Antcibor

    2013-02-01

    Full Text Available Soils are an important compartment of ecosystems and have the ability to immobilize chemicals preventing their movement to other environment compartments. Predicted climatic changes together with other anthropogenic influences on Arctic terrestrial environments may affect biogeochemical processes enhancing leaching and migration of trace elements in permafrost-affected soils. This is especially important since the Arctic ecosystems are considered to be very sensitive to climatic changes as well as to chemical contamination. This study characterizes background levels of trace metals in permafrost-affected soils of the Lena River Delta and its hinterland in northern Siberia (73.5° N–69.5° N representing a remote region far from evident anthropogenic trace metal sources. Investigations on total element contents of iron (Fe, arsenic (As, manganese (Mn, zinc (Zn, nickel (Ni, copper (Cu, lead (Pb, cadmium (Cd, cobalt (Co and mercury (Hg in different soil types developed in different geological parent materials have been carried out. The highest concentrations of the majority of the measured elements were observed in soils belonging to ice-rich permafrost sediments formed during the Pleistocene (ice-complex in the Lena River Delta region. Correlation analyses of trace metal concentrations and soil chemical and physical properties at a Holocene estuarine terrace and two modern floodplain levels in the southern-central Lena River Delta (Samoylov Island showed that the main factors controlling the trace metal distribution in these soils are organic matter content, soil texture and contents of iron and manganese-oxides. Principal Component Analysis (PCA revealed that soil oxides play a significant role in trace metal distribution in both top and bottom horizons. Occurrence of organic matter contributes to Cd binding in top soils and Cu binding in bottom horizons. Observed ranges of the background concentrations of the majority of trace elements were

  16. Search for short-baseline oscillations at the NOvA Near Detector

    Energy Technology Data Exchange (ETDEWEB)

    Kasetti, Siva Prasad [Fermialb; Aurisano, Adam [Cincinnati U.; Suter, Louise [Fermilab; Sousa, Alex [Cincinnati U.

    2016-10-03

    Anomalous results from past neutrino experiments have been interpreted as potential evidence for an additional sterile neutrino with a mass on order of 1 eV, but this evidence remains inconclusive. The NOvA Near Detector is a 300 ton almost fully-active fine- grained liquid scintillator detector, that was designed for electron-neutrino identification. The detector is placed along the Fermilab NuMI beam line 1 km from the target and 14.6 mrad off-axis. At this off-axis angle the detector is exposed to a narrow band beam peaked at 2 GeV. Therefore the NOvA Near Detector will see neutrinos with a L/E range that is sensitive to oscillations between active neutrinos and light sterile neutrinos. In this report we discuss NOvA sensitivity from the joint electron-neutrino appeara ce and muon-neutrino disappearance analysis search for short-baseline sterile neutrino mixing.

  17. The water Cherenkov detector array for studies of cosmic rays at the University of Puebla

    Science.gov (United States)

    Cotzomi, J.; Moreno, E.; Murrieta, T.; Palma, B.; Pérez, E.; Salazar, H.; Villaseñor, L.

    2005-11-01

    We describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla ( 19∘N, 90∘W, 800 g/cm2) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1 PeV, i.e., around the knee of the cosmic ray spectrum. The array consists of 3 water Cherenkov detectors of 1.86 m2 cross-section and 12 liquid scintillator detectors of 1 m2 distributed in a square grid with a detector spacing of 20 m over an area of 4000 m2. We discuss the calibration and stability of the array for both sets of detectors and report on preliminary measurements and reconstruction of the lateral distributions for the electromagnetic (EM) and muonic components of extensive air showers. We also discuss how the hybrid character of the array can be used to measure mass composition of the primary cosmic rays by estimating the relative contents of muons with respect to the EM component of extensive air showers. This facility is also used to train students interested in the field of cosmic rays.

  18. Mars Express/ASPERA-3/NPI and IMAGE/LENA observations of energetic neutral atoms in Earth and Mars orbit

    CERN Document Server

    Holmstrom, M; Barabash, S; Brinkfeldt, K; Moore, T E; Simpson, D

    2007-01-01

    The low energy neutral atom imagers on Mars Express and IMAGE have revealed that the neutral atom populations in interplanetary space come from a variety of sources and challenge our current understanding of heliospheric physics. For example, both in cruise phase and at Mars, the neutral particle instrument NPD on Mars Express observed "unexplained neutral beams" unrelated to Mars which appear to be either of heliospheric or solar wind origin. Likewise, the NPI instrument on Mars Express has revealed streams of neutral atoms with different properties than those observed by NPD. Independently, IMAGE/LENA has reported neutral atom observations that may be interpreted as a "secondary stream" having different characteristics and flowing from a higher ecliptic longitude than the nominal upstream direction. Both sets of observations do not appear to fit in easily with the neutral atom environment from 1.0-1.57 AU as it is currently understood. In this paper we examine some highly suggestive similarities in the IMAG...

  19. Rezension zu: Lena Gunnarsson: The Contradictions of Love. Towards a feminist-realist ontology of sociosexuality. London: Routledge 2014.

    Directory of Open Access Journals (Sweden)

    Hannah Schultes

    2015-11-01

    Full Text Available In ihrer Studie theoretisiert Lena Gunnarsson überzeugend Ursachen und Erscheinungen der anhaltenden Tendenz einer Unterordnung von Frauen unter Männer in den Bereichen Liebe und Sexualität in westlichen Gesellschaften. Ausgehend von einer Kritik an Judith Butlers Queer Theory und einer positiven Bezugnahme auf Anna Jónasdóttirs Theorie der Ausbeutung weiblicher Liebe analysiert die Autorin Ungleichheit stabilisierende Mechanismen in heterosexuellen Paarbeziehungen sowie deren inhärenten Widersprüche. Aus metatheoretischen Überlegungen wird ein grundlegendes Interesse von Männern an der Aufhebung dieser Widersprüche abgeleitet sowie eine auf zwei Ebenen operierende Strategie weiblicher Emanzipation formuliert.

  20. River ice flux and water velocities along a 600 km long reach of Lena River, Siberia, from satellite stereo

    Directory of Open Access Journals (Sweden)

    A. Kääb

    2013-07-01

    Full Text Available Knowledge of water-surface velocities in rivers is useful for understanding a range of river processes. In cold regions, river-ice break up and the related downstream transport of ice debris is often the most important hydrological event of the year, leading to flood levels that typically exceed those for the open-water period and to strong consequences for river infrastructure and ecology. Accurate and complete surface-velocity fields on rivers have rarely been produced. Here, we track river ice debris over a time period of about one minute, which is the typical time lag between the two or more images that form a stereo data set in spaceborne, along-track optical stereo-mapping. Using a series of 9 stereo scenes from the US/Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER onboard the NASA Terra spacecraft with 15 m image resolution, we measure the ice and water velocity field over a 620 km long reach of the lower Lena River, Siberia, just above its entry into the Lena delta. Careful analysis and correction of higher-order image and sensor errors enables an accuracy of ice-debris velocities of up to 0.04 m s−1 from the ASTER data. Maximum ice or water speeds, respectively, reach up to 2.5 m s−1 at the time of data acquisition, 27 May 2011 (03:30 UTC. Speeds show clear along-stream undulations with a wavelength of about 21 km that agree well with variations in channel width and with the location of sand bars along the river reach studied. The methodology and results of this study could be valuable to a number of disciplines requiring detailed information about river flow, such as hydraulics, hydrology, river ecology and natural-hazard management.

  1. Detectors for the Gamma-Ray Resonant Absorption (GRA) Method of Explosives Detection in Cargo: A Comparative Study

    CERN Document Server

    Vartsky, D; Engler, G; Shor, A; Goldschmidt, A; Feldman, G; Bar, D; Orion, I; Wielopolski, L; Vartsky, David; Goldberg, Mark B.; Engler, Gideon; Shor, Asher; Goldschmidt, Aharon; Feldman, Gennady; Bar, Doron; Orion, Itzhak; Wielopolski, Lucian

    2004-01-01

    Gamma-Ray Resonant Absorption (GRA) is an automatic-decision radiographic screening technique that combines high radiation penetration with very good sensitivity and specificity to nitrogenous explosives. The method is particularly well-suited to inspection of large, massive objects (since the incident gamma-ray probe is at 9.17 MeV) such as aviation and marine containers, heavy vehicles and railroad cars. Two kinds of gamma-ray detectors have been employed to date in GRA systems: 1) Resonant-response nitrogen-rich liquid scintillators and 2) BGO detectors. This paper analyses and compares the response of these detector-types to the resonant radiation, in terms of single-pixel figures of merit. The latter are sensitive not only to detector response, but also to accelerator-beam quality, via the properties of the nuclear reaction that produces the resonant gamma-rays. Generally, resonant detectors give rise to much higher nitrogen-contrast sensitivity in the radiographic image than their non-resonant detector ...

  2. Conceptual design of the early implementation of the NEutron Detector Array (NEDA) with AGATA

    Energy Technology Data Exchange (ETDEWEB)

    Hueyuek, Tayfun; Gadea, Andres; Domingo-Pardo, Cesar [Universidad de Valencia, Instituto de Fisica Corpuscular, CSIC, Paterna (Valencia) (Spain); Di Nitto, Antonio [Istituto Nazionale di Fisica Nucleare, Napoli (Italy); Johannes Gutenberg-Universitaet Mainz, Mainz (Germany); Jaworski, Grzegorz; Javier Valiente-Dobon, Jose; De Angelis, Giacomo; Modamio, Victor; Triossi, Andrea [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Nyberg, Johan [Uppsala University, Department of Physics and Astronomy, Uppsala (Sweden); Palacz, Marcin [University of Warsaw, Heavy Ion Laboratory, Warsaw (Poland); Soederstroem, Paer-Anders [RIKEN Nishina Center, Saitama (Japan); Aliaga-Varea, Ramon Jose [Universidad de Valencia, Instituto de Fisica Corpuscular, CSIC, Paterna (Valencia) (Spain); Universidad Politecnica de Valencia, I3M, Valencia (Spain); Atac, Ayse [Ankara University, Department of Physics, Faculty of Sciences, Ankara (Turkey); The Royal Institute of Technology, Stockholm (Sweden); Collado, Javier; Egea, Francisco Javier; Gonzalez, Vicente; Sanchis, Enrique [University of Valencia, Department of Electronic Engineering, Burjassot (Valencia) (Spain); Erduran, Nizamettin [Istanbul Sabahattin Zaim University, Faculty of Engineering and Natural Sciences, Istanbul (Turkey); Ertuerk, Sefa [University of Nigde, Department of Physics, Faculty of Science and Arts, Nigde (Turkey); France, Gilles de [CNRS/IN2P3, GANIL, CEA/DSAM, Caen (France); Gadea, Rafael; Herrero-Bosch, Vicente [Universidad Politecnica de Valencia, I3M, Valencia (Spain); Kaskas, Ayse [Ankara University, Department of Physics, Faculty of Sciences, Ankara (Turkey); Moszynski, Marek [National Centre for Nuclear Research, Otwock-Swierk (Poland); Wadsworth, Robert [University of York, Department of Physics, York (United Kingdom)

    2016-03-15

    The NEutron Detector Array (NEDA) project aims at the construction of a new high-efficiency compact neutron detector array to be coupled with large γ -ray arrays such as AGATA. The application of NEDA ranges from its use as selective neutron multiplicity filter for fusion-evaporation reaction to a large solid angle neutron tagging device. In the present work, possible configurations for the NEDA coupled with the Neutron Wall for the early implementation with AGATA has been simulated, using Monte Carlo techniques, in order to evaluate their performance figures. The goal of this early NEDA implementation is to improve, with respect to previous instruments, efficiency and capability to select multiplicity for fusion-evaporation reaction channels in which 1, 2 or 3 neutrons are emitted. Each NEDA detector unit has the shape of a regular hexagonal prism with a volume of about 3.23l and it is filled with the EJ301 liquid scintillator, that presents good neutron- γ discrimination properties. The simulations have been performed using a fusion-evaporation event generator that has been validated with a set of experimental data obtained in the {sup 58}Ni + {sup 56}Fe reaction measured with the Neutron Wall detector array. (orig.)

  3. Tritium measurement in water using bremsstrahlung X-rays and a silicon drift detector

    Energy Technology Data Exchange (ETDEWEB)

    Niemes, Simon [Karlsruhe Institut of Technology, Institute for Technical Physics - Tritium Laboratory, Karlsruhe (Germany)

    2013-07-01

    Applications like future fusion plants or scientific experiments like KATRIN need a closed tritium infrastructure to cycle and handle tritium safely. At some process stages tritiated water (HTO) is generated, making measuring the tritium content in HTO vital for process control, accountancy and safety. There are several methods used to measure HTO, primarily Liquid Scintillation Counting (LSC). A new technique promising fast, in-line and wasteless measurement compared to LSC is the Beta Induced X-ray Spectroscopy (BIXS). The principle of BIXS is detecting the bremsstrahlung spectrum from the decelerated decay electrons in water and calibrate it to known concentrations. A novel approach utilizing a Silicon Drift Detector (SDD) to measure the emitted X-ray spectrum has several advantages over other detector types like scintillation counters. A SDD is a semiconductor detector with very low noise and good energy resolution, suitable for detecting the low intensity, low energy signal from BIXS. In this talk an overview of the experimental setup and detector is given, and first results are presented.

  4. Conceptual design of the early implementation of the NEutron Detector Array (NEDA) with AGATA

    Science.gov (United States)

    Hüyük, Tayfun; Di Nitto, Antonio; Jaworski, Grzegorz; Gadea, Andrés; Javier Valiente-Dobón, José; Nyberg, Johan; Palacz, Marcin; Söderström, Pär-Anders; Jose Aliaga-Varea, Ramon; de Angelis, Giacomo; Ataç, Ayşe; Collado, Javier; Domingo-Pardo, Cesar; Egea, Francisco Javier; Erduran, Nizamettin; Ertürk, Sefa; de France, Gilles; Gadea, Rafael; González, Vicente; Herrero-Bosch, Vicente; Kaşkaş, Ayşe; Modamio, Victor; Moszynski, Marek; Sanchis, Enrique; Triossi, Andrea; Wadsworth, Robert

    2016-03-01

    The NEutron Detector Array (NEDA) project aims at the construction of a new high-efficiency compact neutron detector array to be coupled with large γ-ray arrays such as AGATA. The application of NEDA ranges from its use as selective neutron multiplicity filter for fusion-evaporation reaction to a large solid angle neutron tagging device. In the present work, possible configurations for the NEDA coupled with the Neutron Wall for the early implementation with AGATA has been simulated, using Monte Carlo techniques, in order to evaluate their performance figures. The goal of this early NEDA implementation is to improve, with respect to previous instruments, efficiency and capability to select multiplicity for fusion-evaporation reaction channels in which 1, 2 or 3 neutrons are emitted. Each NEDA detector unit has the shape of a regular hexagonal prism with a volume of about 3.23l and it is filled with the EJ301 liquid scintillator, that presents good neutron- γ discrimination properties. The simulations have been performed using a fusion-evaporation event generator that has been validated with a set of experimental data obtained in the 58Ni + 56Fe reaction measured with the Neutron Wall detector array.

  5. Immunity raised by recent European subtype 1 PRRSV strains allows better replication of East European subtype 3 PRRSV strain Lena than that raised by an older strain

    DEFF Research Database (Denmark)

    Trus, Ivan; Frydas, Ilias S.; Reddy, Vishwanatha R. A. P.

    2016-01-01

    Stable spatial distribution of porcine reproductive and respiratory syndrome (PRRSV)-1 subtypes in Europe is accompanied by a strong population immunity induced by local PRRSV strains. In the present study, it was examined if the immunity induced by three West European subtype 1 PRRSV strains (2007...... isolate 07V063 and 2013 isolates 13V091 and 13V117) offers protection against the highly virulent East European subtype 3 PRRSV strain Lena. The number of fever days was greater (p ...: 8.3). Reduction of respiratory disease, nasal shedding (mean AUC and mean peak values) and viremia (mean AUC and mean peak values) was more pronounced in 07V063-immune (p strains caused priming of the Lena...

  6. New data on mammoth fauna mammals in the central Lena River basin (Yakutia, Lenskie Stolby National Nature Park and adjacent areas)

    Science.gov (United States)

    Boeskorov, G. G.; Nogovitsyn, P. R.; Mashchenko, E. N.; Belolyubsky, I. N.; Stepanov, A. D.; Plotnikov, V. V.; Protopopov, A. V.; Shchelchkova, M. V.; van der Plicht, J.; Solomonov, N. G.

    2016-07-01

    This paper considers the data on new findings of mammoth fauna remains in the Middle Lena basin used to specify the species composition of large Late Neopleistocene mammals represented by eleven species. The obtained range of radiocarbon dates made it possible to state that mass burials of Pleistocene mammal remains were formed in the region during the Karginsk Interstadial (24 000-55 000 years ago).

  7. Proyecto de modificación de la línea FFCC de Pola de Lena a Puente de los Fierros (Asturias)

    OpenAIRE

    Balagué Martín, Guillermo

    2013-01-01

    Proyecto de adecuación de la actual vía FFCC a ancho FEVE (1000 mm) en el tramo Puente de los Fierros - Pola de Lena (valle del Pajares, Asturias); mejora de estaciones existentes y construcción de nuevos apeaderos. Análisis de viabilidad económica y búsqueda de la dinamización turística.

  8. The exchange of carbon dioxide between wet arctic tundra and the atmosphere at the Lena River Delta, Northern Siberia

    Directory of Open Access Journals (Sweden)

    L. Kutzbach

    2007-06-01

    Full Text Available The exchange fluxes of carbon dioxide between wet arctic polygonal tundra and the atmosphere were investigated by the micrometeorological eddy covariance method. The investigation site was situated in the centre of the Lena River Delta in Northern Siberia (72°22' N, 126°30' E. The study region is characterized by a polar and distinctly continental climate, very cold and ice-rich permafrost and its position at the interface between the Eurasian continent and the Arctic Ocean. The soils at the site are characterized by high organic matter content, low nutrient availability and pronounced water logging. The vegetation is dominated by sedges and mosses. The micrometeorological campaigns were performed during the periods July–October 2003 and May–July 2004 which included the period of snow and soil thaw as well as the beginning of soil refreeze. The main CO2 exchange processes, the gross photosynthesis and the ecosystem respiration, were found to be of a generally low intensity. The gross photosynthesis accumulated to –432 g m−2 over the photosynthetically active period (June–September. The contribution of mosses to the gross photosynthesis was estimated to be about 40%. The diurnal trend of the gross photosynthesis was mainly controlled by the incoming photosynthetically active radiation. During midday the photosynthetic apparatus of the canopy was frequently near saturation and represented the limiting factor on gross photosynthesis. The synoptic weather conditions strongly affected the exchange fluxes of CO2 by changes in cloudiness, precipitation and pronounced changes of air temperature. The ecosystem respiration accumulated to +327 g m−2 over the photosynthetically active period, which corresponds to 76% of the CO2 uptake by photosynthesis. However, the ecosystem respiration continued at substantial rates during autumn when photosynthesis had ceased and the soils

  9. The exchange of carbon dioxide between wet arctic tundra and the atmosphere at the Lena River Delta, Northern Siberia

    Science.gov (United States)

    Kutzbach, L.; Wille, C.; Pfeiffer, E.-M.

    2007-10-01

    The exchange fluxes of carbon dioxide between wet arctic polygonal tundra and the atmosphere were investigated by the micrometeorological eddy covariance method. The investigation site was situated in the centre of the Lena River Delta in Northern Siberia (72°22' N, 126°30' E). The study region is characterized by a polar and distinctly continental climate, very cold and ice-rich permafrost and its position at the interface between the Eurasian continent and the Arctic Ocean. The soils at the site are characterized by high organic matter content, low nutrient availability and pronounced water logging. The vegetation is dominated by sedges and mosses. The micrometeorological campaigns were performed during the periods July-October 2003 and May-July 2004 which included the period of snow and soil thaw as well as the beginning of soil refreeze. The main CO2 exchange processes, the gross photosynthesis and the ecosystem respiration, were found to be of a generally low intensity. The gross photosynthesis accumulated to -432 g m-2 over the photosynthetically active period (June-September). The contribution of mosses to the gross photosynthesis was estimated to be about 40%. The diurnal trend of the gross photosynthesis was mainly controlled by the incoming photosynthetically active radiation. During midday, the photosynthetic apparatus of the canopy was frequently near saturation and represented the limiting factor on gross photosynthesis. The synoptic weather conditions strongly affected the exchange fluxes of CO2 by changes in cloudiness, precipitation and pronounced changes of air temperature. The ecosystem respiration accumulated to +327 g m-2 over the photosynthetically active period, which corresponds to 76% of the CO2 uptake by photosynthesis. However, the ecosystem respiration continued at substantial rates during autumn when photosynthesis had ceased and the soils were still largely unfrozen. The temporal variability of the ecosystem respiration during summer

  10. Electronics and data acquisition system of the extensive air shower detector array at the University of Puebla

    Science.gov (United States)

    Perez, E.; Salazar, H.; Villasenor, L.; Martinez, O.; Conde, R.; Murrieta, T.

    Field programmable gate arrays (FPGAs) are playing an increasing role in DAQ systems in cosmic ray experiments due to their high speed and integration and their low cost and low power comsumption. In this paper we describe in detail the new electronics and data acquisition system based on FPGA boards of the extensive air shower detector array built in the Campus of the University of Puebla. The purpose of this detector array is to measure the energy and arrival direction of primary cosmic rays with energies around 1015 eV. The array consists of 10 liquid scintillator detectors and 6 water Cherenkov detectors (of 1.86 m2 cross section), distributed in a square grid with a detector spacing of 20 m over an area of 4000 m2. The electronics described also makes use of analog to digital converters with a resolution of 10 bits and sampling speeds of 100 MS/s to digitize the PMT signals. We also discuss the advantages of discriminating the PMT signals inside the FPGAs with respect to the conventional use of dedicated discrimination circuits.

  11. 林纳燕麦(Avena sativa L.cv.LENA)在川西北的栽培初探%The Primary Research on Cultivation of Avena Sativa L.cv.LENA in North-west Sichuan

    Institute of Scientific and Technical Information of China (English)

    陈莉敏; 肖冰雪; 郑群英; 张昌兵; 季晓菲; 吴婍

    2016-01-01

    林纳(Avena sativa L.cv.LENA)是优质燕麦品种之一.本研究比较不同播种量(150、225、300kg/hm2)、行距(20、30、40cm)和肥料(尿素、复合肥、有机肥)对林纳燕麦干草产量、株高和叶绿素相对含量(SPAD值)的影响.结果显示:播种量225kg/hm2,行距40cm的林纳燕麦干草产量最高(P<0.05),为8683.5kg/hm2,叶绿素相对含量也相对较高;施用复合肥和尿素能显著提高林纳燕麦干草产量,也有利于燕麦保持较高的叶绿素相对含量.

  12. Fast muon simulation in the JUNO central detector

    Science.gov (United States)

    Lin, Tao; Deng, Zi-Yan; Li, Wei-Dong; Cao, Guo-Fu; You, Zheng-Yun; Li, Xin-Ying

    2016-08-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment designed to measure the neutrino mass hierarchy using a central detector (CD), which contains 20 kton liquid scintillator (LS) surrounded by about 17000 photomultiplier tubes (PMTs). Due to the large fiducial volume and huge number of PMTs, the simulation of a muon particle passing through the CD with the Geant4 toolkit becomes an extremely computation-intensive task. This paper presents a fast simulation implementation using a so-called voxel method: for scintillation photons generated in a certain LS voxel, the PMT’s response is produced beforehand with Geant4 and then introduced into the simulation at runtime. This parameterisation method successfully speeds up the most CPU consuming process, the optical photon’s propagation in the LS, by a factor of 50. In the paper, the comparison of physics performance between fast and full simulation is also given. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA10010900) and National Natural Science Foundation of China (11405279, 11575224)

  13. A collimated neutron detector for RFP plasmas in MST

    Science.gov (United States)

    Capecchi, W. J.; Anderson, J. K.; Bonofiglo, P. J.; Kim, J.; Sears, S.

    2016-11-01

    The neutron emissivity profile in the Madison Symmetric Torus is being reconstructed through the use of a collimated neutron detector. A scintillator-photomultiplier tube (PMT) system is employed to detect the fusion neutrons with the plasma viewing volume defined by a 55 cm deep, 5 cm diameter aperture. Effective detection of neutrons from the viewing volume is achieved through neutron moderation using 1300 lbs of high density polyethylene shielding, which modeling predicts attenuates the penetrating flux by a factor of 104 or more. A broad spectrum of gamma radiation is also present due to the unconfined fusion proton bombardment of the thick aluminum vacuum vessel. A 15 cm cylindrical liquid scintillator of 3.8 cm diameter is used to further increase directional sensitivity. A fast (5 ns rise time) preamplifier and digitization at 500 MHz prevent pulse pile-up even at high count rates (˜104/s). The entire neutron camera system is situated on an adjustable inclining base which provides the differing plasma viewing volumes necessary for reconstruction of the neutron emissivity profile. This profile, directly related to the fast-ion population, allows for an investigation of the critical fast-ion pressure gradient required to destabilize a neutral beam driven Alfvénic mode which has been shown to transport fast ions.

  14. Characterization of particulate organic matter in the Lena River Delta and adjacent nearshore zone, NE Siberia – Part 1: Lignin-derived phenol compositions

    Directory of Open Access Journals (Sweden)

    M. Winterfeld

    2014-10-01

    Full Text Available The Lena River in central Siberia is one of the major pathways translocating terrestrial organic matter (OM from its vast catchment area to the coastal zone of the Laptev Sea and the Arctic Ocean. The permafrost soils of its far south stretching catchment, which store huge amounts of OM, will most likely respond differently to climate warming and remobilize previously frozen OM with distinct properties specific for the source vegetation and soil. To characterize the material discharged by the Lena River, we analyzed the lignin phenol composition in total suspended matter (TSM from surface water collected in spring and summer, surface sediments from the Buor Khaya Bay along with soils from the Lena Delta's first (Holocene and third terraces (Pleistocene ice complex, and plant samples. Our results show that lignin-derived cinnamyl:vanillyl (C/V and syringyl:vanillyl (S/V ratios are >0.14 and 0.25, respectively, in TSM and surface sediments, whereas in delta soils they are >0.16 and >0.51, respectively. These lignin compositions are consistent with significant inputs of organic matter from non-woody angiosperm sources mixed with organic matter derived from woody gymnosperm sources. We applied a simple linear mixing model based on the C/V and S/V ratios and the results indicate the organic matter in delta TSM samples and Buor Khaya Bay surface sediments contain comparable contributions from gymnosperm material, which is primarily derived from the taiga forests south of the delta, and angiosperm material typical for tundra vegetation. Considering the small catchment area covered by tundra (∼12%, the input is substantial and tundra-derived OM input is likely to increase in a warming Arctic. The similar and high acid to aldehyde ratios of vanillyl and syringyl (Ad/AlV, S in Lena Delta summer TSM (>0.7 and >0.5, respectively and Buor Khaya Bay surface sediments (>1.0 and >0.9, respectively suggest that the OM is highly degraded and Lena River summer

  15. A abordagem teórica de Lena Vania Ribeiro Pinheiro sobre os conceitos inter e transdisciplinaridade

    Directory of Open Access Journals (Sweden)

    Roberto Lopes dos Santos Junior

    Full Text Available Análise da abordagem da pesquisadora brasileira Lena Vania Ribeiro Pinheiro sobre os conceitos inter e transdisciplinaridade, em sua produção intelectual, a partir de uma revisão de literatura de trabalhos produzidos pela autora entre os anos 1990 até 2009. Serão analisadas as principais influências teóricas (Hilton Japiassú, Julie Thompson Klein, Edgar Morin e Olga Pombo que nortearam e basearam seu estudo sobre esses conceitos, e a evolução dessa abordagem com o decorrer de sua produção bibliográfica. Paralelamente a essa análise, a partir das ideias da autora, será feito um breve estudo histórico sobre o desenvolvimento dos conceitos inter e transdisciplinaridade, além da identificação das áreas de conhecimento que possuem interrelação teórica e prática com a Ciência da Informação. Conclui-se, a partir dessa análise preliminar, que a pesquisadora possui um sólido e consistente arcabouço teórico sobre o tema.

  16. Potential of a Neutrino Detector in the ANDES Underground Laboratory for Geophysics and Astrophysics of Neutrinos

    CERN Document Server

    Machado, P A N; Nunokawa, H; Funchal, R Zukanovich

    2012-01-01

    The construction of the Agua Negra tunnels that will link Argentina and Chile under the Andes, the world longest mountain range, opens the possibility to build the first deep underground labo- ratory in the Southern Hemisphere. This laboratory has the acronym ANDES (Agua Negra Deep Experiment Site) and its overburden could be as large as \\sim 1.7 km of rock, or 4500 mwe, providing an excellent low background environment to study physics of rare events like the ones induced by neutrinos and/or dark matter. In this paper we investigate the physics potential of a few kiloton size liquid scintillator detector, which could be constructed in the ANDES laboratory as one of its possible scientific programs. In particular, we evaluate the impact of such a detector for the studies of geoneutrinos and galactic supernova neutrinos assuming a fiducial volume of 3 kilotons as a reference size. We emphasize the complementary roles of such a detector to the ones in the Northern Hemisphere neutrino facilities through some adv...

  17. Low level radioactivity measurements with phoswich detectors using coincident techniques and digital pulse processing analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fuente, R. de la [University of Leon, Escuela de Ingenieria Industrial, Leon 24071 (Spain); Celis, B. de [University of Leon, Escuela de Ingenieria Industrial, Leon 24071 (Spain)], E-mail: bcelc@unileon.es; Canto, V. del; Lumbreras, J.M. [University of Leon, Escuela de Ingenieria Industrial, Leon 24071 (Spain); Celis, Alonso B. de [King' s College London, IoP, De Crespigny Park, SE58AF (United Kingdom); Martin-Martin, A. [Laboratorio LIBRA, Edificio I-D, Paseo Belen 3. 47011 Valladolid (Spain); Departamento de Fisica Teorica, Atomica y Optica, Facultad de Ciencias. Po Prado de la Magdalena, s/n. 47005 Valladolid (Spain)], E-mail: alonsomm@libra.uva.es; Gutierrez-Villanueva, J.L. [Laboratorio LIBRA, Edificio I-D, Paseo Belen 3. 47011 Valladolid (Spain); Departamento de Fisica Teorica, Atomica y Optica, Facultad de Ciencias. Po Prado de la Magdalena, s/n. 47005 Valladolid (Spain)], E-mail: joselg@libra.uva.es

    2008-10-15

    A new system has been developed for the detection of low radioactivity levels of fission products and actinides using coincidence techniques. The device combines a phoswich detector for {alpha}/{beta}/{gamma}-ray recognition with a fast digital card for electronic pulse analysis. The phoswich can be used in a coincident mode by identifying the composed signal produced by the simultaneous detection of {alpha}/{beta} particles and X-rays/{gamma} particles. The technique of coincidences with phoswich detectors was proposed recently to verify the Nuclear Test Ban Treaty (NTBT) which established the necessity of monitoring low levels of gaseous fission products produced by underground nuclear explosions. With the device proposed here it is possible to identify the coincidence events and determine the energy and type of coincident particles. The sensitivity of the system has been improved by employing liquid scintillators and a high resolution low energy germanium detector. In this case it is possible to identify simultaneously by {alpha}/{gamma} coincidence transuranic nuclides present in environmental samples without necessity of performing radiochemical separation. The minimum detectable activity was estimated to be 0.01 Bq kg{sup -1} for 0.1 kg of soil and 1000 min counting.

  18. Forward fitting of experimental data from a NE213 neutron detector installed with the magnetic proton recoil upgraded spectrometer at JETa)

    Science.gov (United States)

    Binda, F.; Ericsson, G.; Eriksson, J.; Hellesen, C.; Conroy, S.; Sundén, E. Andersson

    2014-11-01

    In this paper, we present the results obtained from the data analysis of neutron spectra measured with a NE213 liquid scintillator at JET. We calculated the neutron response matrix of the instrument combining MCNPX simulations, a generic proton light output function measured with another detector and the fit of data from ohmic pulses. For the analysis, we selected a set of pulses with neutral beam injection heating (NBI) only and we applied a forward fitting procedure of modeled spectral components to extract the fraction of thermal neutron emission. The results showed the same trend of the ones obtained with the dedicated spectrometer TOFOR, even though the values from the NE213 analysis were systematically higher. This discrepancy is probably due to the different lines of sight of the two spectrometers (tangential for the NE213, vertical for TOFOR). The uncertainties on the thermal fraction estimates were from 4 to 7 times higher than the ones from the TOFOR analysis.

  19. 用于微中子震荡实验的液体闪烁探测器的探测效率研究%The study of detection efficiency of the liquid scintillator for neutrino oscillation experiment

    Institute of Scientific and Technical Information of China (English)

    毛泽普; 仲国庆; Leung R; 邓炳坤

    2007-01-01

    为了台湾微中子震荡实验的设计,研究了正电子的探测效率与触发模型的关系,模拟结果说明,当单元正电子能量阈值为55keV时,以15cn×15 cm 单元截面的5×5和7×7单元组成的触发模型的正电子的探测效率可以分别达到60%和70%.它们相关的参数是设计较好的选择.%In order to Provide the criteria for the detector and trigger logical design of Taiwan Neutrion Oscillation (TEXNON) experiment, the relationship of the positron detection efficiency with the construction of the detector the trigger model have been investigated. Correspondent results have been obtained, such as the cell size of 15×15cm2,single cell deposited energy threshold set at 55keV,the 5×5 and 7×7 cells for triggering gamma ray, the positron detection is about 60% and 70% respectively.This set of parameters is recommended as the better choose of the detector design.

  20. Constraints from Os-isotope variations on the origin of Lena Trough abyssal peridotites and implications for the composition and evolution of the depleted upper mantle

    Science.gov (United States)

    Lassiter, J. C.; Byerly, B. L.; Snow, J. E.; Hellebrand, E.

    2014-10-01

    The Lena Trough is a highly oblique, sparsely magmatic, ultra-slow spreading center located at the smallest distance between North America and Eurasia in the Arctic basin. Competing models suggest that it is either floored by oceanic mantle abyssal peridotites (APs) exposed by lithospheric necking, or by subcontinental mantle exposed in a still juvenile rift. To distinguish between these hypotheses, we have examined mineral major and trace element and whole rock Os-isotope variations in Lena Trough peridotites. Lena Trough peridotites are predominantly LREE-depleted, similar to other AP suites, and have 187Os/188Os ranging from ∼0.118 to 0.130 (Ave.=0.1244). This distribution is nearly identical to that of abyssal peridotites globally. Both the REE patterns and the Os-isotope distribution of the Lena Trough peridotites differ starkly from subcontinental mantle xenoliths sampled at Svalbard adjacent to Lena Trough. This suggests that Lena Trough is a site of oceanic spreading, although mid-ocean ridge volcanism as such has not yet begun. Highly refractory APs from several settings have Os- and Hf-isotope compositions indicating ancient (>1 Ga) melt depletion. Some researchers have proposed that at least some APs do not directly sample the convecting upper mantle source of MORB, but instead sample highly melt-depleted residues either entrained in the convecting mantle or present as a buoyant “slag” floating atop the less-depleted MORB-source mantle. However, ocean island peridotite xenoliths and APs reveal an essentially identical, non-Gaussian distribution of Os-isotopes and also span a similar range in Hf-isotopes. The similar mean and distribution of Os-isotopes between APs and ocean island xenoliths indicate that these two sample types derive from the same heterogeneous mantle reservoir. This similarity is inconsistent with the AP “slag hypothesis” due to the significantly greater depth of origin of ocean island xenoliths with respect to APs. Global

  1. Application of the efficiency tracing method to the liquid scintillation metrology of 3H and 14C dual-labelled samples; Aplicacion del metodo de la figura de merito a la metrologia por centelleo liquido de muestras doblemente marcadas con 3H y 14C.

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Casallo, M. T.; Los Arcos, J. M.; Grau, A.

    1989-07-01

    Two calculation procedures have been tested for the application of the efficiency tracing method to the activity determination of 3H and 14C dual- -labelled samples in the liquid scintillation metrology. A procedure Ieads to the statement of a linear equations system as a function of the quenching parameter, while the other one uses a least-square algorithm to fit the total count rate against the quenching parameter. The first procedure is strongly sensitive to the statistical uncertainty on the partial efficiencies and produces discrepancies which may reach more than 100% compared to the real values. The second procedure leads to more reliable results, showing discrepancies between 0.1% and 0.6% for the 3H activity and between 0.6% and 5% for the 14C activity, as that the efficiency tracing method can be applied to the metro- logy of dual-labelled samples of 3H and 14C by means of this procedure. (Author) 7 refs.

  2. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  3. Advances toward a transportable antineutrino detector system for reactor monitoring and safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Reyna, D. [Sandia National Laboratories, Livermore, CA 94550 (United States); Bernstein, A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Lund, J.; Kiff, S.; Cabrera-Palmer, B. [Sandia National Laboratories, Livermore, CA 94550 (United States); Bowden, N. S.; Dazeley, S.; Keefer, G. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2011-07-01

    Nuclear reactors have served as the neutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these very weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Our SNL/LLNL collaboration has demonstrated that such antineutrino based monitoring is feasible using a relatively small cubic meter scale liquid scintillator detector at tens of meters standoff from a commercial Pressurized Water Reactor (PWR). With little or no burden on the plant operator we have been able to remotely and automatically monitor the reactor operational status (on/off), power level, and fuel burnup. The initial detector was deployed in an underground gallery that lies directly under the containment dome of an operating PWR. The gallery is 25 meters from the reactor core center, is rarely accessed by plant personnel, and provides a muon-screening effect of some 20-30 meters of water equivalent earth and concrete overburden. Unfortunately, many reactor facilities do not contain an equivalent underground location. We have therefore attempted to construct a complete detector system which would be capable of operating in an aboveground location and could be transported to a reactor facility with relative ease. A standard 6-meter shipping container was used as our transportable laboratory - containing active and passive shielding components, the antineutrino detector and all electronics, as well as climate control systems. This aboveground system was deployed and tested at the San Onofre Nuclear Generating Station (SONGS) in southern California in 2010 and early 2011. We will first present an overview of the initial demonstrations of our below ground detector. Then we will describe the aboveground system and the technological developments of the two antineutrino

  4. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  5. The neutrino experiment Double Chooz and data analysis with the near detector

    Energy Technology Data Exchange (ETDEWEB)

    Franke, Michael Werner

    2016-03-07

    During the last years there has been a huge progress in the field of neutrino physics. Neutrino oscillations are well established and almost all parameters, except a possible CP-violating phase, are determined to high precision. One experiment providing a precise measurement of the neutrino mixing angle θ{sub 13} is the Double Chooz reactor antineutrino experiment. The reactor antineutrinos are detected via the inverse beta decay in two identical liquid scintillator based detectors. A few years ago, the value of θ{sub 13} was unknown and only an upper limit existed. Double Chooz was the first reactor antineutrino experiment presenting a result for a nonzero value of θ{sub 13}. The value for sin{sup 2}2θ{sub 13} from the latest Double Chooz publication is 0.090{sup +0.032}{sub -0.029}. As part of this thesis, an infrastructure for filling the Double Chooz near detector was established and 190 m{sup 3} of detector liquids were prepared successfully. The filling process was optimized to allow an efficient filling of the near detector. The total operation time was reduced to only 22 days. Compared to the far detector filling time of 2 months, this is a great improvement. The development of a completely new level measurement system was as well part of this thesis. Due to the excellent performance of the level measurement system, the hard restrictions for the safety of the Double Chooz detector were met during the entire filling process. Several power glitches and network failures did not harm the system and did not result in any loss of data. These irregularities and the simple maintenance and repair possibilities certify the success of the design concept for the new level measurement system. For this thesis, data from the Double Chooz near detector with a total live time of 110.4 days was used. The mass concentrations of uranium and thorium in the near detector were determined using BiPo coincidences. These events originate from the β-decay of {sup 214}Bi and {sup

  6. Gaseous Detectors: Charged Particle Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Hilke, H J

    2011-01-01

    Gaseous Detectors in 'Charged Particle Detectors - Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Subsection '3.1.2 Gaseous Detectors' of Section '3.1 Charged Particle Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.1.2 Gaseous Detectors 3.1.2.1 Introduction 3.1.2.2 Basic Processes 3.1.2.2.1 Gas ionization by charged particles 3.1.2.2.1.1 Primary clusters 3.1.2.2.1.2 Cluster size distribution 3.1.2.2.1.3 Total number of ion pairs 3.1.2.2.1.4 Dependence of energy deposit on particle velocity 3.1.2.2.2 Transport of...

  7. Digital pulse-timing technique for the neutron detector array NEDA

    Energy Technology Data Exchange (ETDEWEB)

    Modamio, V., E-mail: victor.modamio@lnl.infn.it [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Valiente-Dobón, J.J. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Jaworski, G. [Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa (Poland); Heavy Ion Laboratory, University of Warsaw, 02-093 Warszawa (Poland); Hüyük, T. [Instituto de Física Corpuscular, CSIC-Universitat de València, E-46980 Valencia (Spain); Triossi, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Egea, J. [Instituto de Física Corpuscular, CSIC-Universitat de València, E-46980 Valencia (Spain); Department of Electronic Engineering, Universitat de València, E-46100 Burjassot (Spain); Di Nitto, A. [Johannes Gutenberg-Universität Mainz, D-55099 Mainz (Germany); Söderström, P.-A. [RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, 351-0198 Saitama (Japan); Agramunt Ros, J. [Instituto de Física Corpuscular, CSIC-Universitat de València, E-46980 Valencia (Spain); Angelis, G. de [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); France, G. de [GANIL, CEA/DSAM and CNRS/IN2P3, F-14076 Caen (France); Erduran, M.N. [Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University, 34303 Istanbul (Turkey); and others

    2015-03-01

    A new digital pulse-timing algorithm, to be used with the future neutron detector array NEDA, has been developed and tested. The time resolution of four 5 in. diameter photomultiplier tubes (XP4512, R4144, R11833-100, and ET9390-kb), coupled to a cylindrical 5 in. by 5 in. BC501A liquid scintillator detector was measured by employing digital sampling electronics and a constant fraction discriminator (CFD) algorithm. The zero crossing of the CFD algorithm was obtained with a cubic spline interpolation, which was continuous up to the second derivative. The performance of the algorithm was studied at sampling rates of 500 MS/s and 200 MS/s. The time resolution obtained with the digital electronics was compared to the values acquired with a standard analog CFD. The result of this comparison shows that the time resolution from the analog and the digital measurements at 500 MS/s and at 200 MS/s are within 15% for all the tested photomultiplier tubes.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-11

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

  9. Photochemical and microbial transformation of terrestrial dissolved organic matter - Lena River vs. rivers in mid and low latitudes

    Science.gov (United States)

    Vähätalo, A. V.; Aarnos, H.; Paolucci, E. M.; Musibono, D. E.; Khan, S. R.; Gelinas, Y.; Shantz, A.; Huang, Q.; Schneider, W.; Rezende, C. E.; Petrescu, E.; Reader, H. E.

    2012-04-01

    biodegradability model based on a reactivity continuum to the observed biodegradation of DOC. In the dark control samples, the biodegradation of DOC was moderate, but the irradiation speeded up the decomposition of DOC a lot. The potential photodecomposition of DOM can be realized with a few hundred kilometers from the mouth of those rivers discharging to the mid- or low-latitude ocean. For the DOM of Lena River, the potential photodegradation is realized only partially in the receiving Laptev Sea having seasons with no or little solar radiation and additionally covered by sea ice over most of year.

  10. Detection of Geoneutrinos: Can We Make the Gnus Work for Us?

    CERN Document Server

    Learned, John G

    2008-01-01

    The detection of electron anti-neutrinos from natural radioactivity in the earth has been a goal of neutrino researchers for about half a century. It was accomplished by the KamLAND Collaboration in 2005, and opens the way towards studies of the Earth's radioactive content, with very important implications for geology. New detectors are operating (KamLAND and Borexino), building (SNO+) and being proposed (Hanohano, LENA, Earth and others) that will go beyond the initial observation and allow interesting geophysical and geochemical research, in a means not otherwise possible. Herein we describe the approaches being taken (large liquid scintillation instruments), the experimental and technical challenges (optical detectors, directionality), and prospects for growth of this field. There is related spinoff in particle physics (neutrino oscillations and hierarchy determination), astrophysics (solar neutrinos, supernovae, exotica), and in the practical matter of remote monitoring of nuclear reactors.

  11. Pixel Detectors

    OpenAIRE

    Wermes, Norbert

    2005-01-01

    Pixel detectors for precise particle tracking in high energy physics have been developed to a level of maturity during the past decade. Three of the LHC detectors will use vertex detectors close to the interaction point based on the hybrid pixel technology which can be considered the state of the art in this field of instrumentation. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as the very harsh...

  12. SU-D-BRC-07: System Design for a 3D Volumetric Scintillation Detector Using SCMOS Cameras

    Energy Technology Data Exchange (ETDEWEB)

    Darne, C; Robertson, D; Alsanea, F; Beddar, S [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: The purpose of this project is to build a volumetric scintillation detector for quantitative imaging of 3D dose distributions of proton beams accurately in near real-time. Methods: The liquid scintillator (LS) detector consists of a transparent acrylic tank (20×20×20 cm{sup 3}) filled with a liquid scintillator that when irradiated with protons generates scintillation light. To track rapid spatial and dose variations in spot scanning proton beams we used three scientific-complementary metal-oxide semiconductor (sCMOS) imagers (2560×2160 pixels). The cameras collect optical signal from three orthogonal projections. To reduce system footprint two mirrors oriented at 45° to the tank surfaces redirect scintillation light to cameras for capturing top and right views. Selection of fixed focal length objective lenses for these cameras was based on their ability to provide large depth of field (DoF) and required field of view (FoV). Multiple cross-hairs imprinted on the tank surfaces allow for image corrections arising from camera perspective and refraction. Results: We determined that by setting sCMOS to 16-bit dynamic range, truncating its FoV (1100×1100 pixels) to image the entire volume of the LS detector, and using 5.6 msec integration time imaging rate can be ramped up to 88 frames per second (fps). 20 mm focal length lens provides a 20 cm imaging DoF and 0.24 mm/pixel resolution. Master-slave camera configuration enable the slaves to initiate image acquisition instantly (within 2 µsec) after receiving a trigger signal. A computer with 128 GB RAM was used for spooling images from the cameras and can sustain a maximum recording time of 2 min per camera at 75 fps. Conclusion: The three sCMOS cameras are capable of high speed imaging. They can therefore be used for quick, high-resolution, and precise mapping of dose distributions from scanned spot proton beams in three dimensions.

  13. Metal Detectors.

    Science.gov (United States)

    Harrington-Lueker, Donna

    1992-01-01

    Schools that count on metal detectors to stem the flow of weapons into the schools create a false sense of security. Recommendations include investing in personnel rather than hardware, cultivating the confidence of law-abiding students, and enforcing discipline. Metal detectors can be quite effective at afterschool events. (MLF)

  14. Optical Detectors

    Science.gov (United States)

    Tabbert, Bernd; Goushcha, Alexander

    Optical detectors are applied in all fields of human activities from basic research to commercial applications in communication, automotive, medical imaging, homeland security, and other fields. The processes of light interaction with matter described in other chapters of this handbook form the basis for understanding the optical detectors physics and device properties.

  15. Physical processes of thermokarst lakes in the continuous permafrost zone of northern Siberia – observations and modeling (Lena River Delta, Siberia

    Directory of Open Access Journals (Sweden)

    J. Boike

    2015-04-01

    Full Text Available The thermal regimes of five lakes located within the continuous permafrost zone of northern Siberia (Lena River Delta have been investigated using hourly water temperature and water level records covering a three year period (2009–2012, together with bathymetric survey data. The lakes included thermokarst lakes located on Holocene river terraces that may be connected to Lena River water during spring flooding, and a thermokarst lake located on deposits of the Pleistocene Ice Complex. The data were used for numerical modeling with FLake software, and also to determine the physical indices of the lakes. The lakes vary in area, depths and volumes. The winter thermal regime is characterized by an ice cover up to 2 m thick that survives for more than 7 months of the year, from October until about mid-June. Lake-bottom temperatures increase at the start of the ice-covered period due to upward-directed heat flux from the underlying thawed sediment. The effects of solar radiation return prior to ice break-up, effectively warming the water beneath the ice cover and inducing convective mixing. Ice break-up starts the beginning of June and takes until the middle or end of June for completion. Mixing occurs within the entire water column from the start of ice break-up and continues during the ice-free periods, as confirmed by the Wedderburn numbers. Some of the lakes located closest to the Lena River are subjected to varying levels of spring flooding with river water, on an annual basis. Numerical modeling using FLake software indicates that the vertical heat flux across the bottom sediment tends towards an annual mean of zero, with maximum downward fluxes of about 5 W m−2 in summer and with heat released back into the water column at a~rate of less than 1 W m−2 during the ice-covered period. The lakes are shown to be efficient heat absorbers and effectively distribute the heat through mixing. Monthly bottom water temperatures during the ice

  16. Neutron/gamma discrimination properties of composite scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Iwanowska, J; Swiderski, L; Moszynski, M; Szczesniak, T; Sibczynski, P [The Soltan Institute for Nuclear Studies, Otwock-Swierk, PL-05-400 Poland (Poland); Galunov, N Z; Karavaeva, N L, E-mail: j.iwanowska@ipj.gov.pl [The Institute for Scintillation Materials of National Academy of Sciences of Ukraine, 60 Lenin Ave., 61001, Kharkov (Ukraine)

    2011-07-15

    A composite scintillator is a solid solution, which contains the grains of organic molecular single crystal introduced into a polymer matrix and placed inside the housing. Hereunder, we present n/{gamma} discrimination properties of four composite scintillators; two of the them are based on p-terphenyl and two others-on stilbene. The results obtained with a stilbene single crystal and a liquid scintillator BC501A are shown as a comparison. Initial conclusion, which is drawn from the paper, is that composite scintillators could be an alternative substitution for commonly used liquid scintillators.

  17. A Study of Nuclear Recoil Backgrounds in Dark Matter Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Westerdale, Shawn S. [Princeton U.

    2016-01-01

    development that informed the design of the DarkSide-50 boron-loaded liquid scintillator neutron veto. We describe the specific implementation of this veto system in DarkSide-50, including a description of its performance, and show that it can reject neutrons with a high enough e_ciency to allow DarkSide-50 to run background-free for three years.

  18. Tracing the catchment-scale hydrology of polygonal tundra and implications for lateral fluxes of carbon and nitrogen, Lena River Delta, Siberia

    Science.gov (United States)

    Runkle, Benjamin R. K.; Helbig, Manuel; Knoblauch, Christian; Kutzbach, Lars

    2014-05-01

    Surface-water hydrology changes the thermal regime of permafrost, carries varying amounts of nutrients depending on its flowpath, and provides a fuel for biogeochemical reactions, including the biological production of methane and carbon dioxide by soil microbes. In this work we present the findings of hydrological investigations in the ice-wedge polygon tundra of the Samoylov Research Island in Russia's Lena River Delta. We compare the catchment-scale behaviour of two adjacent watersheds through stable isotope analysis conducted over two years of sampling (2012-13). This work also incorporates the use of conservative natural tracers such as silica concentration and sheds light on mechanisms for the transport of dissolved organic carbon into the Lena River system. Hydrological discharge measurements taken over three years (2011-13) reveal generally similar patterns in rainfall response and permafrost thaw between two adjacent watersheds - one smaller (0.02 km2) and dominantly comprised of the characteristic polygonal tundra and the second larger one (0.6 km2) also containing two large surface-water reservoirs, namely a degraded ice-wedge network and a lake. However, stable isotope measurements of hydrogen (δD) and oxygen (δ18O) reveal that the latter watershed maintains a significant surface-water isotopic signature throughout the summer period, with greater influence of evaporation on watershed dynamics. The smaller, characteristic polygon catchment shows ever-increasing influence of deeper flow paths as the thaw depth increases over the season. These small catchments release low amounts of dissolved organic carbon and nitrogen both in terms of concentration (carbon budget (water, carbon, and energy cycles. Furthermore, modeling strategies will benefit from simpler process-based representations of landscape processes when upscaling to examine regional landscape-atmosphere interactions.

  19. DUMAND detector

    CERN Multimedia

    This object is one of the 256 other detectors of the DUMAND (Deep Underwater Muon And Neutrino Detection) experiment. The goal of the experiment was the construction of the first deep ocean high energy neutrino detector, to be placed at 4800 m depth in the Pacific Ocean off Keahole Point on the Big Island of Hawaii. A few years ago, a European conference with Cosmic experiments was organized at CERN as they were projects like DUMAND in Hawaii. Along with the conference, a temporary exhibition was organised as well. It was a collaboration of institutions from Germany, Japan, Switzerland and the U.S.A. CERN had borrowed equipment and objects from different institutes around the world, including this detector of the DUMAND experiment. Most of the equipment were sent back to the institutes, however this detector sphere was offered to a CERN member of the personnel.

  20. Setting Limits On The Power Of A Geo-reactor With Kamland Detector

    CERN Document Server

    Maricic, J

    2005-01-01

    The Earth's magnetic field has existed for at least 3 billion years with high and on average stable intensity, though with many fluctuations and reversals. One of the models, albeit rather controversial, proposed as the energy source of the Earth's magnetic field is a natural nuclear reactor inside the Earth's core [1] and [2]. This author maintains that this is the only model that generates sufficient power to energize the geo-magnetic field for 3 billion years. Even more, the reactor's ability to produce variable power levels including stops and restarts in its operations, provides a viable explanation, according to [2], for the random reversals of the geo-magnetic field that have been recorded numerous times during the Earth's history. In this study, Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) is used to set limits on the power of the putative geo-reactor. KamLAND is designed to detect anti-neutrinos from reactors around Japan, and thus can make a direct measurement of the anti-neutrino ra...

  1. Hanohano: A Deep Ocean Anti-Neutrino Detector for Unique Neutrino Physics and Geophysics Studies

    CERN Document Server

    Learned, John G; Pakvasa, Sandip

    2008-01-01

    The science potential of a 10 kiloton deep-ocean liquid scintillation detector for ~1 MeV energy scale electron anti-neutrinos has been studied. Such an instrument, designed to be portable and function in the deep ocean (3-5 km) can make unique measurements of the anti-neutrinos from radioactive decays in the Earth'.s mantle. Ths information speaks to some of the most fundamental questions in geology about the origin of the Earth, plat e tectonics, the geomagnetic field and even somewhat indirectly to global warming. Measurements in multiple locations will strengthen the potential insights. On the particle physics side, we have identified a unique role in the study of anti-neutrinos from a nuclear power complex, at a range of 55-60 km off shore. Not only can precision measurements be made of most neutrino mixing parameters, including $\\theta_{13}$ (depending on magnitude), but the neutrino mass hierarchy can be determined in a method not heretofore discussed, and one which does not rely upon matter effects. T...

  2. Fast neutron tomography with real-time pulse-shape discrimination in organic scintillation detectors

    Science.gov (United States)

    Joyce, Malcolm J.; Agar, Stewart; Aspinall, Michael D.; Beaumont, Jonathan S.; Colley, Edmund; Colling, Miriam; Dykes, Joseph; Kardasopoulos, Phoevos; Mitton, Katie

    2016-10-01

    A fast neutron tomography system based on the use of real-time pulse-shape discrimination in 7 organic liquid scintillation detectors is described. The system has been tested with a californium-252 source of dose rate 163 μSv/h at 1 m and neutron emission rate of 1.5×107 per second into 4π and a maximum acquisition time of 2 h, to characterize two 100×100×100 mm3 concrete samples. The first of these was a solid sample and the second has a vertical, cylindrical void. The experimental data, supported by simulations with both Monte Carlo methods and MATLAB®, indicate that the presence of the internal cylindrical void, corners and inhomogeneities in the samples can be discerned. The potential for fast neutron assay of this type with the capability to probe hydrogenous features in large low-Z samples is discussed. Neutron tomography of bulk porous samples is achieved that combines effective penetration not possible with thermal neutrons in the absence of beam hardening.

  3. Coincidence measurements in {alpha}/{beta}/{gamma} spectrometry with phoswich detectors using digital pulse shape discrimination analysis

    Energy Technology Data Exchange (ETDEWEB)

    Celis, B. de [University of Leon, Escuela de Ingenieria Industrial, Leon 24071 (Spain)], E-mail: bcelc@unileon.es; Fuente, R. de la [University of Leon, Escuela de Ingenieria Industrial, Leon 24071 (Spain); Williart, A. [UNED, F. Ciencias Fisicas, Madrid 28040 (Spain); Celis Alonso, B. de [King' s College London, IoP, De Crespigny Park, London SE5 8AF (United Kingdom)

    2007-09-21

    A novel system has been developed for the detection of low radioactivity levels using coincidence techniques. The device combines a phoswich detector for {alpha}/{beta}/{gamma} ray recognition with a fast digital card for electronic pulse analysis. The detector is able to discriminate different types of radiation in a mixed {alpha}/{beta}/{gamma} field and can be used in a coincidence mode by identifying the composite signal produced by the simultaneous detection of {beta} particles in a plastic scintillator and {gamma} rays in an NaI(Tl) scintillator. Use of a coincidence technique with phoswich detectors was proposed recently to verify the Nuclear Test Ban Treaty, which made it necessary to monitor the low levels of xenon radioisotopes produced by underground nuclear explosions. Previous studies have shown that combining CaF{sub 2}(Eu) for {beta} ray detection and NaI(Tl) for {gamma} ray detection makes it difficult to identify the coincidence signals because of the similar fluorescence decay times of the two scintillators. With the device proposed here, it is possible to identify the coincidence events owing to the short fluorescence decay time of the plastic scintillator. The sensitivity of the detector may be improved by employing liquid scintillators, which allow low radioactivity levels from actinides to be measured when present in environmental samples. The device developed is simpler to use than conventional coincidence equipment because it uses a single detector and electronic circuit, and it offers fast and precise analysis of the coincidence signals by employing digital pulse shape analysis.

  4. Study of a method of detection for natural carbon-14 using a liquid scintillator, recent variations in the natural radio-activity due to artificial carbon-14 (1963); Etude d'une methode de detection du carrons 14 naturel, utilisant un scintillateur liquide - variations recentes de l'activite naturelle dues au carbone 14 artificiel (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-06-15

    Among the various natural isotopes of carbon, a radioactive isotope, carbon-14, is formed by the action of secondary neutrons from cosmic rays on nitrogen in the air. Until 1950, the concentration of this isotope in ordinary carbon underwent weak fluctuations of about 2-3 per cent. The exact measurement of this concentration 6 X 10{sup 12} Ci/gm of carbon, and of its fluctuations, are difficult and in the first part of this report a highly sensitive method is given using a liquid scintillator. Since 1950 this natural activity has shown large fluctuations because of the carbon-14 formed during nuclear explosions, and in the second part, the evolution in France of this specific activity of carbon in the atmosphere and biosphere is examined. In the last part is studied the local increase in carbon activity in the atmosphere around the Saclay site, an increase caused by the carbon-14 given off as C{sup 14}O{sub 2}, by the reactors cooled partially with exterior air. (author) [French] Parmi les differents isotopes naturels du carbone, un isotope radioactif, le carbone 14, est forme par l'action de neutrons secondaires due aux rayons cosmiques sir l'azote de l'air. Jusqu'en 1950, la concentration de cet isotope dans le carbone ordinaire est soumise a des fluctuations de faible amplitude, de l'ordre de 2 a 3 pour cent. Les mesures precises de cette concentration, 6. 10{sup -12} Ci/g de carbone, et de ses fluctuations sont delicates, et dans la premiere partie de ce rapport, on decrit une methode de detection a grande sensibilite utilisant un scintillateur liquide. Depuis 1950, cette activite naturelle subit des fluctuations importantes dues au carbone 14 forme lors des explosions nucleaires, et dans la seconde partie, on examine l'evolution en France de l'activite specifique du carbone de l'atmosphere et ce la biosphere. Dans la derniere partie, on etudie l'accroissement local de l'activite du carbone de l'air aux

  5. Establishment of methodology for determination of {sup 93}Zr in radioactive wastes by Liquid Scintillation Counting (LSC) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS); Estabelecimento de metodologia para determinacao de {sup 93}Zr em rejeitos radioativos por Espectrometria de Cintilacao Liquida (LSC) e Espectrometria de Massa com Plasma Indutivamente Acoplado (ICP-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Thiago Cesar de

    2014-06-01

    The zirconium-93 is a long-lived pure β-particle-emitting radionuclide produced from {sup 235}U fission and from neutron activation of the stable isotope {sup 92}Zr and thus occurring as one of the radionuclides found in nuclear reactors. Due to its long half life, {sup 93}Zr is one of the radionuclides of interest for the performance of assessment studies of waste storage or disposal. Measurement of {sup 93}Zr is difficult owing to its trace level concentration and its low activity in nuclear wastes and further because its certified standards are not frequently available. The aim of this work was to develop a selective radiochemical separation methodology for the determination of {sup 93}Zr in nuclear waste and analyze it by Liquid Scintillation Counting (LSC) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). To set up the radiochemical separation procedure for zirconium, a tracer solution of {sup 95}Zr and its 724 keV γ-ray measurements by γ- spectrometry were used in order to follow the behavior of zirconium during the radiochemical separation. For the LSC technique a {sup 55}Fe solution, which is one of the major interfering measures zirconium, was used to verify the decontamination factor during the separation process. The efficiency detection for {sup 63}Ni was used to determination of {sup 93}Zr activity in the matrices analyzed. The limit of detection of the 0.05 Bq 1{sup −1} was obtained for {sup 63}Ni standard solutions by using a sample:cocktail ratio of 3:17 mL for Optiphase Hisafe 3 cocktail. For the ICP-MS technique a zirconium stable solution was used to verify the zirconium behavior and recovery during radiochemical separation and a solution of Ba, Co, Eu, Fe, Mn, Nb, Sr and Y was used to verify the decontamination factor during the separation process. A standard solution {sup 93}Nb as isotope for determining the {sup 93}Zr by ICP-MS was used for calibration and analysis. The detection limit of 0.039 ppb was obtained for the standard

  6. Calorimeter detectors

    CERN Document Server

    de Barbaro, P; The ATLAS collaboration

    2013-01-01

    Although the instantaneous and integrated luminosity in HL-LHC will be far higher than the LHC detectors were originally designed for, the Barrel calorimeters of the four experiments are expected to continue to perform well  throughout the Phase II program. The conditions for the End-Cap calorimeters are far more challenging and whilst some detectors will require relatively modest changes, others require far more substantial upgrades. We present the results of longevity and performance studies for the calorimeter systems of the four main LHC experiments and outline the upgrade options under consideration. We include a discussion of the R&D required to make the final technology choices for the upgraded detectors.

  7. Pixel detectors

    CERN Document Server

    Passmore, M S

    2001-01-01

    positions on the detector. The loss of secondary electrons follows the profile of the detector and increases with higher energy ions. studies of the spatial resolution predict a value of 5.3 lp/mm. The image noise in photon counting systems is investigated theoretically and experimentally and is shown to be given by Poisson statistics. The rate capability of the LAD1 was measured to be 250 kHz per pixel. Theoretical and experimental studies of the difference in contrast for ideal charge integrating and photon counting imaging systems were carried out. It is shown that the contrast differs and that for the conventional definition (contrast = (background - signal)/background) the photon counting device will, in some cases, always give a better contrast than the integrating system. Simulations in MEDICI are combined with analytical calculations to investigate charge collection efficiencies (CCE) in semiconductor detectors. Different pixel sizes and biasing conditions are considered. The results show charge shari...

  8. Method for measuring multiple scattering corrections between liquid scintillators

    Science.gov (United States)

    Verbeke, J. M.; Glenn, A. M.; Keefer, G. J.; Wurtz, R. E.

    2016-07-01

    A time-of-flight method is proposed to experimentally quantify the fractions of neutrons scattering between scintillators. An array of scintillators is characterized in terms of crosstalk with this method by measuring a californium source, for different neutron energy thresholds. The spectral information recorded by the scintillators can be used to estimate the fractions of neutrons multiple scattering. With the help of a correction to Feynman's point model theory to account for multiple scattering, these fractions can in turn improve the mass reconstruction of fissile materials under investigation.

  9. Cherenkov and Scintillation Light Separation in Organic Liquid Scintillators

    CERN Document Server

    Caravaca, J; Land, B J; Yeh, M; Gann, G D Orebi

    2016-01-01

    The CHErenkov / Scintillation Separation experiment (CHESS) has been used to demonstrate the separation of Cherenkov and scintillation light in both linear alkylbenzene (LAB) and LAB with 2g/L of PPO as a fluor (LAB/PPO). This is the first such demonstration for the more challenging LAB/PPO cocktail and improves on previous results for LAB. A time resolution of 338 +/- 12 ps FWHM results in an efficiency for identifying Cherenkov photons in LAB/PPO of 70 +/- 3% and 63 +/- 8% for time- and charge-based separation, respectively, with scintillation contamination of 36 +/- 5% and 38 +/- 4%. LAB/PPO data is consistent with a rise time of 0.75 +/- 0.25 ns.

  10. Aqueous liquid scintillation counting with fluor-containing nanosuspensions

    Energy Technology Data Exchange (ETDEWEB)

    Weekley, James C.; Wuenschel, Sara; Rosenstiel, Paul E.; Mumper, Russell J.; Jay, Michael E-mail: jay@email.uky.edu

    2004-06-01

    A microemulsion comprised of water, Brij 78, pentanol and styrene into which PPO and bis-MSB had been dissolved was prepared. Polymerization of the styrene resulted in a suspension of fluor-containing polystyrene nanoparticles (<100 nm). After a concentration step, the aqueous nanosuspension was able to detect {sup 14}C with counting efficiencies over 50% of those of a commercially available scintillation cocktail. Monte Carlo calculations demonstrated that the size and concentration of the nanoparticles were appropriate for optimum detection efficiency.

  11. Properties of Quantum-Dot-Doped Liquid Scintillators

    Science.gov (United States)

    Coy, Christopher

    2014-03-01

    Novel scintillators based on semiconducting nanocrystals called quantum dots have unique optical and chemical properties that make them interesting for future neutrino experiments especially those searching for neutrino-less double beta decay. In this talk, we report the results of laboratory-scale measurements for three candidate quantum-dot-doped scintillators. We focus on the key properties required for large-scale neutrino experiments, which are the emission spectrum, the attenuation length and the stability. I would like to follow the talk by Andrey Elagin on directionality in scintillators and precede Athena Ierokomos' talk on light yield in scintillators.

  12. 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...

  13. XMASS detector

    CERN Document Server

    Abe, K; Hiraide, K; Hirano, S; Kishimoto, Y; Kobayashi, K; Moriyama, S; Nakagawa, K; Nakahata, M; Nishiie, H; Ogawa, H; Oka, N; Sekiya, H; Shinozaki, A; Suzuki, Y; Takeda, A; Takachio, O; Ueshima, K; Umemoto, D; Yamashita, M; Yang, B S; Tasaka, S; Liu, J; Martens, K; Hosokawa, K; Miuchi, K; Murata, A; Onishi, Y; Otsuka, Y; Takeuchi, Y; Kim, Y H; Lee, K B; Lee, M K; Lee, J S; Fukuda, Y; Itow, Y; Nishitani, Y; Masuda, K; Takiya, H; Uchida, H; Kim, N Y; Kim, Y D; Kusaba, F; Motoki, D; Nishijima, K; Fujii, K; Murayama, I; Nakamura, S

    2013-01-01

    The XMASS project aims to detect dark matter, pp and $^{7}$Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  14. XMASS detector

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hieda, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Hiraide, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hirano, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kishimoto, Y.; Kobayashi, K.; Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nakagawa, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Ogawa, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); and others

    2013-07-11

    The XMASS project aims to detect dark matter, pp and {sup 7}Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  15. Semiconductor Detectors; Detectores de Semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Cortina, E.

    2007-07-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  16. Test of a prototype neutron spectrometer based on diamond detectors in a fast reactor

    CERN Document Server

    Osipenko, M; Ripani, M; Pillon, M; Ricco, G; Caiffi, B; Cardarelli, R; Verona-Rinati, G; Argiro, S

    2015-01-01

    A prototype of neutron spectrometer based on diamond detectors has been developed. This prototype consists of a $^6$Li neutron converter sandwiched between two CVD diamond crystals. The radiation hardness of the diamond crystals makes it suitable for applications in low power research reactors, while a low sensitivity to gamma rays and low leakage current of the detector permit to reach good energy resolution. A fast coincidence between two crystals is used to reject background. The detector was read out using two different electronic chains connected to it by a few meters of cable. The first chain was based on conventional charge-sensitive amplifiers, the other used a custom fast charge amplifier developed for this purpose. The prototype has been tested at various neutron sources and showed its practicability. In particular, the detector was calibrated in a TRIGA thermal reactor (LENA laboratory, University of Pavia) with neutron fluxes of $10^8$ n/cm$^2$s and at the 3 MeV D-D monochromatic neutron source na...

  17. An investigation of the digital discrimination of neutrons and {gamma} rays with organic scintillation detectors using an artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Liu, G.; Aspinall, M.D.; Ma, X. [Department of Engineering, Lancaster University, Bailrigg, Lancaster LA1 4YR (United Kingdom); Joyce, M.J. [Department of Engineering, Lancaster University, Bailrigg, Lancaster LA1 4YR (United Kingdom)], E-mail: m.joyce@lancaster.ac.uk

    2009-08-21

    The discrimination of neutron and {gamma}-ray events in an organic scintillator has been investigated by using a method based on an artificial neural network (ANN). Voltage pulses arising from an EJ-301 organic liquid scintillation detector in a mixed radiation field have been recorded with a fast digital sampling oscilloscope. Piled-up events have been disentangled using a pile-up management unit based on a fitting method. Each individual pulse has subsequently been sent to a discrimination unit which discriminates neutron and {gamma}-ray events with a method based on an artificial neural network. This discrimination technique has been verified by the corresponding mixed-field data assessed by time of flight (TOF). It is shown that the characterization of the neutrons and photons achieved by the discrimination method based on the ANN is consistent with that afforded by TOF. This approach enables events that are often as a result of scattering or pile-up to be identified and returned to the data set and affords digital discrimination of mixed radiation fields in a broad range of environments on the basis of training obtained with a single TOF dataset.

  18. Study of very low energy neutrinos from the Sun and from the Earth with the Borexino detector.

    CERN Document Server

    CERN. Geneva

    2011-01-01

    Borexino is a liquid scintillator unsegmented detector, running at the Gran Sasso underground Laboratories (LNGS). Thanks to its unprecedented low level of radioactive contamination, Borexino currently is the only experiment able to perform a real time measurement of solar neutrino interactions below few MeV. In solar neutrinos Borexino measured the neutrino flux from 7Be (862 keV) with total uncertainty smaller than 5%, the flux from 8B with a lower threshold down to 3 MeV, the day/night asymmetry of the 7Be neutrino flux with a total experimental uncertainty of 1%. These measurements introduce strong constraints also on the solar neutrino flux from the pp and CNO reactions. The impact of these Borexino results are extremely relevant both in solar physics, in connection with the understanding of Sun-like stars, and in neutrino physics. In particular, the precision measurement of the 7Be solar neutrino flux allows a real time investigation of neutrino oscillations below few MeV and provides a unique opportuni...

  19. Permafrost sequences on Kurungnakh Island, Lena Delta (NE Siberia, Russia) as key site of the late Quaternary environmental history of West Beringia

    Science.gov (United States)

    Wetterich, S.; Kuzmina, S.; Andreev, A. A.; Kienast, F.; Meyer, H.; Schirrmeister, L.; Kuznetsova, T.; Sierralta, M.

    2009-04-01

    Late Quaternary permafrost sequences are widely distributed in the arctic lowlands of Siberia. Because the existence of permafrost has been sensitive to climate changes during the Quaternary past, such frozen deposits are regarded as an archive of palaeoenvironmental dynamics. Late Quaternary palaeoenvironments of the Siberian Arctic were reconstructed by combining data from several fossil bioindicators (pollen, plant macro-fossils, ostracods, insects, and mammal bones) with sedimentological and cryolithological data from permafrost deposits. The late Pleistocene to Holocene sequence on Kurungnakh Island (Lena Delta, NE Siberia) reflects the environmental history of West Beringia and covers glacial/interglacial and stadial/interstadial climate variations with a focus on the Middle Weichselian interstadial (50-32 kyr BP). The record mirrors the development of periglacial landscapes under changing sedimentation regimes which were meandering fluvial during the Early Weichselian, colluvial or proluvial on gently inclined plaines during the Middle and Late Weichselian, and thermokarst-affected during the Holocene. Palaeoecological records indicate the existence of tundra-steppe vegetation under cold continental climate conditions during the Middle Weichselian interstadial. Due to sedimentation gaps in the sequence between 32 and 17 kyr BP and 17 and 8 kyr BP, the Late Weichselian stadial is incompletely represented in the studied outcrops. Nevertheless, by several palaeoecological indications arctic tundra-steppe vegetation under extremely cold-arid conditions prevailed during the late Pleistocene. The tundra-steppe disappeared completely due to lasting paludification during the Holocene. Initially subarctic shrub tundra formed, which later retreated in course of the late Holocene cooling.

  20. Baseline characteristics of climate, permafrost and land cover from a new permafrost observatory in the Lena River Delta, Siberia (1998–2011

    Directory of Open Access Journals (Sweden)

    J. Boike

    2013-03-01

    Full Text Available Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies within the Siberian zone of continuous permafrost. The landscape on Samoylov Island consists mainly of late Holocene river terraces with polygonal tundra, ponds and lakes, and an active floodplain. The island has been the focus of numerous multidisciplinary studies since 1993, which have focused on climate, land cover, ecology, hydrology, permafrost and limnology. This paper aims to provide a framework for future studies by describing the characteristics of the island's meteorological parameters (temperature, radiation and snow cover, soil temperature, and soil moisture. The land surface characteristics have been described using high resolution aerial images in combination with data from ground-based observations. Of note is that deeper permafrost temperatures have increased between 0.3 to 1.3 °C over the last five years. However, no clear warming of air and active layer temperatures is detected since 1998, though winter air temperatures during recent years have not been as cold as in earlier years. Data related to this article are archived under: http://doi. pangaea.de/10.1594/PANGAEA.806233 .

  1. Development and performance tests of NSTAR, a new type of compact neutron detector

    Science.gov (United States)

    Pawelczak, Iwona Agnieszka

    Development and performance of the NSTAR ("Neutron Sandwich Transmuter/Activation-gamma Radiator") are discussed, a neutron detector based on a new approach to Gd-loaded scintillators. This detector has high detection efficiency for neutrons, from thermal up to multi-MeV energies with practically zero energy threshold. The NSTAR operating principle is similar to that of Gd-loaded liquid scintillation detectors but avoids many of their disadvantages and hazards. The NSTAR scintillator has the dual function, both to thermalize fast neutrons and to generate responses to the dissipated neutron energy and the emission of associated delayed Gd neutron capture gamma-rays. Consequently, the NSTAR features a time dependent two-component response to neutrons, which consists of a prompt, energy dependent light flash followed by a delayed, energy independent signal. This characteristic response allows one to "tag" neutrons, distinguish them from gamma-rays, and to obtain neutron multiplicity information for multiple-neutron bursts. The detector modules consist of stacks of plastic scintillator slabs (Saint Gobain BC-408) alternating with thin Gd-loaded (0.5 wt.%) converter films (PDMS-SYLGARD 184). The stacks are viewed by fast photomultipliers (Philips XP2041) on one or both ends. The detector design combines high light output collection efficiency with large active volume. The NSTAR modules have been tested with neutrons produced by radioactive sources and a pulsed-beam neutron generator. Tests reveal an effective discrimination against gamma-rays, even in a high intensity background environment, when measurements are made relative to a reference signal. The NSTAR is capable of counting neutrons at rates of R ≤ 7 x 104 n/s with losses below 1% and can measure event by event two moments of the neutron multiplicity distribution. A detection efficiency of epsilon = (26 +/- 3)% was measured for DD-neutrons at an electronic threshold of Eth = 0.2 MeVee. The average neutron

  2. Radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Taleyarkhan, Rusi P.

    2017-06-27

    Alpha particle detecting devices are disclosed that have a chamber that can hold a fluid in a tensioned metastable state. The chamber is tuned with a suitable fluid and tension such that alpha emitting materials such as radon and one or more of its decay products can be detected. The devices can be portable and can be placed in areas, such as rooms in dwellings or laboratories and used to measure radon in these areas, in situ and in real time. The disclosed detectors can detect radon at and below 4 pCi/L in air; also, at and below 4,000 pCi/L or 300 pCi/L in water.

  3. Monitoring Bedfast Ice and Ice Phenology in Lakes of the Lena River Delta Using TerraSAR-X Backscatter and Coherence Time Series

    Directory of Open Access Journals (Sweden)

    Sofia Antonova

    2016-11-01

    Full Text Available Thermokarst lakes and ponds are major elements of permafrost landscapes, occupying up to 40% of the land area in some Arctic regions. Shallow lakes freeze to the bed, thus preventing permafrost thaw underneath them and limiting the length of the period with greenhouse gas production in the unfrozen lake sediments. Radar remote sensing permits to distinguish lakes with bedfast ice due to the difference in backscatter intensities from bedfast and floating ice. This study investigates the potential of a unique time series of three-year repeat-pass TerraSAR-X (TSX imagery with high temporal (11 days and spatial (10 m resolution for monitoring bedfast ice as well as ice phenology of lakes in the zone of continuous permafrost in the Lena River Delta, Siberia. TSX backscatter intensity is shown to be an excellent tool for monitoring floating versus bedfast lake ice as well as ice phenology. TSX-derived timing of ice grounding and the ice growth model CLIMo are used to retrieve the ice thicknesses of the bedfast ice at points where in situ ice thickness measurements were available. Comparison shows good agreement in the year of field measurements. Additionally, for the first time, an 11-day sequential interferometric coherence time series is analyzed as a supplementary approach for the bedfast ice monitoring. The coherence time series detects most of the ice grounding as well as spring snow/ice melt onset. Overall, the results show the great value of TSX time series for monitoring Arctic lake ice and provide a basis for various applications: for instance, derivation of shallow lakes bathymetry, evaluation of winter water resources and locating fish winter habitat as well as estimation of taliks extent in permafrost.

  4. Fate of terrigenous organic matter across the Laptev Sea from the mouth of the Lena River to the deep sea of the Arctic interior

    Science.gov (United States)

    Bröder, Lisa; Tesi, Tommaso; Salvadó, Joan A.; Semiletov, Igor P.; Dudarev, Oleg V.; Gustafsson, Örjan

    2016-09-01

    Ongoing global warming in high latitudes may cause an increasing supply of permafrost-derived organic carbon through both river discharge and coastal erosion to the Arctic shelves. Mobilized permafrost carbon can be either buried in sediments, transported to the deep sea or degraded to CO2 and outgassed, potentially constituting a positive feedback to climate change. This study aims to assess the fate of terrigenous organic carbon (TerrOC) in the Arctic marine environment by exploring how it changes in concentration, composition and degradation status across the wide Laptev Sea shelf. We analyzed a suite of terrestrial biomarkers as well as source-diagnostic bulk carbon isotopes (δ13C, Δ14C) in surface sediments from a Laptev Sea transect spanning more than 800 km from the Lena River mouth (cutin acids and high-molecular-weight (HMW) wax lipids (tracers of vascular plants) decrease by 89-99 % along the transect. Molecular-based degradation proxies for TerrOC (e.g., the carbon preference index of HMW lipids, the HMW acids / alkanes ratio and the acid / aldehyde ratio of lignin phenols) display a trend to more degraded TerrOC with increasing distance from the coast. We infer that the degree of degradation of permafrost-derived TerrOC is a function of the time spent under oxic conditions during protracted cross-shelf transport. Future work should therefore seek to constrain cross-shelf transport times in order to compute a TerrOC degradation rate and thereby help to quantify potential carbon-climate feedbacks.

  5. Estimating Spatially Heterogeneous Contributions to Ecosystem Scale Fluxes Directly From Eddy Covariance Measurements: A Case Study in Siberian wet Polygonal Tundra on Samoylov Island, Lena River Delta

    Science.gov (United States)

    Sachs, T.; Eugster, W.

    2008-12-01

    The eddy covariance method is used widely to measure the turbulent exchange fluxes of climate relevant gases such as carbon dioxide and methane. One important assumption in eddy covariance theory is homogeneity of the surface over which measurements are conducted. However, in reality the method is often applied in very heterogeneous areas and the effect of that heterogeneity on the measurement time series is not fully agreed on in the scientific community. Since the eddy covariance method relies on the time-for- space substitution concept (Taylor's frozen turbulence field assumption), spatial disturbance of the assumed homogeneity should leave similar traces in the time series data that could be detected with state-of-the-art times series statistics approaches, primarily frequency analysis. This should be easiest to detect where the observed heterogeneity is characterized by the steepest possible small-scale spatial contrast of fluxes while also exhibiting certain regularity. Thus, polygonal tundra with its regular micro-relief of very wet polygon depressions with high rates of photosynthesis and methane emission on the one hand and relatively "dry" elevated polygon rims with lower rates of photosynthesis, higher rates of respiration, and extremely low methane emissions on the other hand is considered well-suited to explore the performance of this technique of flux footprint separation. We present a case study using eddy covariance data of water vapour, carbon dioxide and methane from the Lena River Delta, Siberia, and high-resolution aerial photography to demonstrate that spatial heterogeneity correlates with deviations in eddy covariance co-spectra from the idealized co-spectra. This new method - if successful beyond a single case study - could become widely used wherever fluxes are measured over spatially heterogeneous surfaces. It would be especially helpful to move towards more accurate upscaling in areas where emission rates and processes vary greatly on

  6. The exchange of energy, water and carbon dioxide between wet arctic tundra and the atmosphere at the Lena River Delta, Northern Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Kutzbach, L.

    2006-07-01

    The ecosystem-scale exchange fluxes of energy, water and carbon dioxide between wet arctic tundra and the atmosphere were investigated by the micrometeorological eddy covariance method. The investigation site was the centre of the Lena River Delta in Northern Siberia characterised by a polar and distinctly continental climate, very cold and ice-rich permafrost and its position at the interface between the Eurasian continent and the Arctic Ocean. The measurements were performed on the surface of a Holocene river terrace characterised by wet polygonal tundra. The soils at the site are characterised by high organic matter content, low nutrient availability and pronounced water logging. The vegetation is dominated by sedges and mosses. The fluctuations of the H{sub 2}O and CO{sub 2} concentrations were measured with a closed-path infrared gas analyser. The fast-response eddy covariance measurements were supplemented by a set of slow-response meteorological and soil-meteorological measurements. The combined datasets of the two campaigns 2003 and 2004 were used to characterise the seasonal course of the energy, water and CO{sub 2} fluxes and the underlying processes for the synthetic measurement period May 28..October 21 2004/2003 including the period of snow and soil thawing as well as the beginning of refreezing. The synthetic measurement period 2004/2003 was characterised by a long snow ablation period and a late start of the growing season. On the other hand, the growing season ended also late due to high temperatures and snow-free conditions in September. The cumulative summer energy partitioning was characterised by low net radiation, large ground heat flux, low latent heat flux and very low sensible heat flux compared to other tundra sites. These findings point out the major importance of the very cold permafrost for the summer energy budget of the tundra in Northern Siberia. (orig./SR)

  7. CLIC Detector Power Requirements

    CERN Document Server

    Gaddi, A

    2013-01-01

    An estimate for the CLIC detector power requirements is outlined starting from the available data on power consumptions of the four LHC experiments and considering the differences between a typical LHC Detector (CMS) and the CLIC baseline detector concept. In particular the impact of the power pulsing scheme for the CLIC Detector electronics on the overall detector consumption is considered. The document will be updated with the requirements of the sub-detector electronics once they are more defined.

  8. Pixel Vertex Detectors

    OpenAIRE

    Wermes, Norbert

    2006-01-01

    Pixel vertex detectors are THE instrument of choice for the tracking of charged particles close to the interaction point at the LHC. Hybrid pixel detectors, in which sensor and read-out IC are separate entities, constitute the present state of the art in detector technology. Three of the LHC detectors use vertex detectors based on this technology. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as ...

  9. MUON DETECTOR

    CERN Multimedia

    F. Gasparini

    DT As announced in the previous Bulletin MU DT completed the installation of the vertical chambers of barrel wheels 0, +1 and +2. 242 DT and RPC stations are now installed in the negative barrel wheels. The missing 8 (4 in YB-1 and 4 in YB-2) chambers can be installed only after the lowering of the two wheels into the UX cavern, which is planned for the last quarter of the year. Cabling on the surface of the negative wheels was finished in May after some difficulties with RPC cables. The next step was to begin the final commissioning of the wheels with the final trigger and readout electronics. Priority was giv¬en to YB0 in order to check everything before the chambers were covered by cables and services of the inner detectors. Commissioning is not easy since it requires both activity on the central and positive wheels underground, as well as on the negative wheels still on the surface. The DT community is requested to commission the negative wheels on surface to cope with a possible lack of time a...

  10. The MINOS Detectors

    CERN Document Server

    Grashorn, A H E W

    2005-01-01

    The Main Injector Neutrino Oscillation Search (MINOS) experiment's primary goal is the precision measurement of the neutrino oscillation parameters in the atmospheric neutrino sector. This long-baseline experiment uses Fermilab's NuMI beam, measured with a Near Detector at Fermilab, and again 735 km later using a Far Detector in the Soudan Mine Underground Lab in northern Minnesota. The detectors are magnetized iron/scintillator calorimeters. The Far Detector has been operational for cosmic ray and atmospheric neutrino data from July of 2003, the Near Detector from September 2004, and the NuMI beam started in early 2005. This poster presents details of the two detectors.

  11. GADRAS Detector Response Function.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Dean J.; Harding, Lee; Thoreson, Gregory G; Horne, Steven M.

    2014-11-01

    The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.

  12. The TALE Tower Detector

    Science.gov (United States)

    Bergman, D. R.

    The TA Low Energy Extension will include a Tower FluorescenceDetector. Extensive air showers at the lowest usful energies for fluorescence detectors will in general be close to the detector. This requires viewing all elevation angles to be able to reconstruct showers. The TALE Tower Detector, operating in conjunction with other TALE detectors will view elevation angles up to above 70 degrees, with an azimuthal coverage of about 90 degrees. Results from a prototype mirror operated in conjunction with the HiRes detector will also be presented.

  13. Drift Chambers detectors; Detectores de deriva

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I.; Martinez laso, L.

    1989-07-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs.

  14. Thermal kinetic inductance detector

    Energy Technology Data Exchange (ETDEWEB)

    Cecil, Thomas; Gades, Lisa; Miceli, Antonio; Quaranta, Orlando

    2016-12-20

    A microcalorimeter for radiation detection that uses superconducting kinetic inductance resonators as the thermometers. The detector is frequency-multiplexed which enables detector systems with a large number of pixels.

  15. Forward tracking detectors

    Indian Academy of Sciences (India)

    Klaus Mönig

    2007-11-01

    Forward tracking is an essential part of a detector at the international linear collider (ILC). The requirements for forward tracking are explained and the proposed solutions in the detector concepts are shown.

  16. The OSMOND detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Dalgliesh, R. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Duxbury, D.M., E-mail: dom.duxbury@stfc.ac.uk [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Helsby, W.I. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Holt, S.A.; Kinane, C.J. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Marsh, A.S. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Rhodes, N.J.; Schooneveld, E.M. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Spill, E.J.; Stephenson, R. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom)

    2013-01-11

    The development and testing of the Off Specular MicrOstrip Neutron Detector (OSMOND) is described. Based on a microstrip gas chamber the aim of the project was to produce a high counting rate detector capable of replacing the existing rate limited scintillator detectors currently in use on the CRISP reflectometer for off specular reflectometry experiments. The detector system is described together with results of neutron beam tests carried out at the ISIS spallation neutron source.

  17. The CAPRICE RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Basini, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Codino, A.; Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.; Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy)

    1995-09-01

    A compact RICH detector has been developed and used for particle identification in a balloon borne spectrometer to measure the flux of antimatter in the cosmic radiation. This is the first RICH detector ever used in space experiments that is capable of detecting unit charged particles, such as antiprotons. The RICH and all other detectors performed well during the 27 hours long flight.

  18. Spatio-temporal variability of CH4 fluxes and environmental drivers on a modern flood plain of the Siberian Lena River Delta

    Science.gov (United States)

    Rößger, Norman; Wille, Christian; Kutzbach, Lars

    2016-04-01

    In the course of the amplified climate change in the Arctic, methane emissions may considerably increase due to more suitable production conditions comprising enhanced temperatures, greater abundance of moisture and increased availability of the carbon stock to microorganisms. Since methane exhibits a much higher global warming potential than carbon dioxide, a comprehensive understanding of its spatio-temporal dynamics as well as its key controls is of great importance. We study the carbon turnover with a focus on methane on the modern flood plain of Samoylov Island in the Lena River Delta (72°22'N, 126°28'E) using the eddy covariance technique. The heterogeneous area around the flux tower (footprint) is characterised by annual flooding, a variety of non-cryoturbated permafrost-affected soils with different degrees of organic matter accumulation, a tundra vegetation dominated by shrubs and sedges and a slightly undulating relief forming elevated, well drained areas und wet, partially inundated depressions. The measurements ran between June 2014 and September 2015 when methane fluxes were determined using a LICOR 7700 open-path CH4 analyser. The main emissions occurred between June and September determined by spring thaw and refreezing in autumn. The highest methane emissions took place in early August reaching up to 0.03 μmol m-2 s-1. Over the season, the mean methane flux amounted to 0.012 μmol m-2 s-1. This average is based on a large variability of methane fluxes which is to be attributed to the complexity of the footprint. The methane sources are unevenly distributed; thus, the capture of methane fluxes is highly dependent on atmospheric conditions such as stratification and wind direction. Explaining the variability in methane fluxes is based on three modelling approaches: step-wise regression, neural network and deterministic modelling using exponential relationships for flux drivers. For the identification of suitable flux drivers, a comprehensive data

  19. Equalized near maximum likelihood detector

    OpenAIRE

    2012-01-01

    This paper presents new detector that is used to mitigate intersymbol interference introduced by bandlimited channels. This detector is named equalized near maximum likelihood detector which combines nonlinear equalizer and near maximum likelihood detector. Simulation results show that the performance of equalized near maximum likelihood detector is better than the performance of nonlinear equalizer but worse than near maximum likelihood detector.

  20. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  1. Comparative analysis of two diffusion methods for radon Rn-222 estimation in atmospheric air by means of gamma-ray spectroscopy and liquid scintillation counting; Analiza porownawcza dwoch metod dyfuzyjnych pomiaru radonu Rn-222 w powietrzu z wykorzystaniem spektrometru promieni gamma i metody cieklej scyntylacji

    Energy Technology Data Exchange (ETDEWEB)

    Gorzkowski, B.; Pachocki, K.; Pensko, J.; Majle, T.; Rozycki, Z. [Panstwowy Zaklad Higieny, Warsaw (Poland)

    1995-12-31

    The comparative measurements of radon Rn-222 concentration in indoor air some buildings and in radon labour chamber have been conducted using two diffusions methods. The results of parallel measurements using radon charcoal detectors and gamma-ray spectroscopy with liquid alpha scintillation counting (Pico-Rad) have been presented. It was concluded that both methods offer the similar measurements possibilities of radon concentrations in the air from about 30 Bq/m{sup 3} to about 600 Bq/m{sup 3} with the real average divergence between both methods of about {+-}11%. (author). 10 refs, 6 figs, 1 tab.

  2. Capillary detectors for high resolution tracking

    CERN Document Server

    Annis, P

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 × 105 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on Electron Bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented.

  3. The DØ detector

    Science.gov (United States)

    Abachi, S.; Abolins, M.; Acharya, B. S.; Adam, I.; Ahn, S.; Aihara, H.; Alvarez, G.; Alves, G. A.; Amos, N.; Anderson, W.; Antipov, Yu.; Aronson, S. H.; Astur, R.; Avery, R. E.; Baden, A.; Balderston, J.; Baldin, B.; Bantly, J.; Barasch, E.; Bartlett, J. F.; Bazizi, K.; Behnke, T.; Bezzubov, V.; Bhat, P. C.; Blazey, G.; Blessing, S.; Boehnlein, A.; Borcherding, F.; Borders, J.; Bozko, N.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoy, V.; Butler, J. M.; Callot, O.; Chakraborty, D.; Chekulaev, S.; Chen, J.; Chen, L.-P.; Chen, W.; Choudhary, B. C.; Christenson, J. H.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M.; Cutts, D.; Dahl, O. I.; Daniels, B.; De, K.; Demarteau, M.; Denisenko, K.; Denisenko, N.; Denisov, D.; Denisov, S.; Dharmaratna, W.; Diehl, H. T.; Diesburg, M.; Dixon, R.; Draper, P.; Ducros, Y.; Durston-Johnson, S.; Eartly, D.; Eberhard, P. H.; Edmunds, D.; Efimov, A.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eroshin, O.; Evdokimov, V.; Fahey, S.; Fanourakis, G.; Fatyga, M.; Featherly, J.; Feher, S.; Fein, D.; Ferbel, T.; Finley, D.; Finocchiaro, G.; Fisk, H. E.; Flattum, E.; Forden, G. E.; Fortner, M.; Franzini, P.; Fuess, S.; Gallas, E.; Gao, C. S.; Geld, T. L.; Genser, K.; Gerber, C. E.; Gibbard, B.; Glebov, V.; Glicenstein, J. F.; Gobbi, B.; Goforth, M.; Good, M. L.; Goozen, F.; Gordon, H.; Graf, N.; Grannis, P. D.; Green, D. R.; Green, J.; Greenlee, H.; Grossman, N.; Grudberg, P.; Guida, J. A.; Guida, J. M.; Guryn, W.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hall, R. E.; Hansen, S.; Hauptman, J.; Hedin, D.; Heinson, A. P.; Heintz, U.; Heuring, T.; Hirosky, R.; Hodel, K.; Hoftun, J. S.; Hubbard, J. R.; Huehn, T.; Huson, R.; Igarashi, S.; Ito, A. S.; James, E.; Jiang, J.; Johns, K.; Johnson, C. R.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jung, C. K.; Kahn, S.; Kanekal, S.; Kernan, A.; Kerth, L.; Kirunin, A.; Klatchko, A.; Klima, B.; Klochkov, B.; Klopfenstein, C.; Klyukhin, V.; Kochetkov, V.; Kohli, J. M.; Kononenko, W.; Kotcher, J.; Kotov, I.; Kourlas, J.; Kozelov, A.; Kozlovsky, E.; Krafczyk, G.; Krempetz, K.; Krishnaswamy, M. R.; Kroon, P.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Landsberg, G.; Lanou, R. E.; Laurens, P.; Lee-Franzini, J.; Li, J.; Li, R.; Li-Demarteau, Q. Z.; Lima, J. G. R.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Y.-C.; Lloyd-Owen, D.; Lobkowicz, F.; Loken, S. C.; Lokos, S.; Lueking, L.; Maciel, A. K. A.; Madaras, R. J.; Madden, R.; Malamud, E.; Mangeot, Ph.; Manning, I.; Mansoulié, B.; Manzella, V.; Mao, H.-S.; Marcin, M.; Markosky, L.; Marshall, T.; Martin, H. J.; Martin, M. I.; Martin, P. S.; Marx, M.; May, B.; Mayorov, A.; McCarthy, R.; McKinley, J.; Mendoza, D.; Meng, X.-C.; Merritt, K. W.; Milder, A.; Mincer, A.; Mondal, N. K.; Montag, M.; Mooney, P.; Mudan, M.; Mulholland, G. T.; Murphy, C.; Murphy, C. T.; Nang, F.; Narain, M.; Narasimham, V. S.; Neal, H. A.; Nemethy, P.; Nešić, D.; Ng, K. K.; Norman, D.; Oesch, L.; Oguri, V.; Oltman, E.; Oshima, N.; Owen, D.; Pang, M.; Para, A.; Park, C. H.; Partridge, R.; Paterno, M.; Peryshkin, A.; Peters, M.; Pi, B.; Piekarz, H.; Pischalnikov, Yu.; Pizzuto, D.; Pluquet, A.; Podstavkov, V.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Que, Y.-K.; Quintas, P. Z.; Rahal-Callot, G.; Raja, R.; Rajagopalan, S.; Rao, M. V. S.; Rasmussen, L.; Read, A. L.; Regan, T.; Repond, S.; Riadovikov, V.; Rijssenbeek, M.; Roe, N. A.; Rubinov, P.; Rutherfoord, J.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Sculli, J.; Selove, W.; Shea, M.; Shkurenkov, A.; Shupe, M.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, A.; Smith, D.; Smith, R. P.; Snow, G. R.; Snyder, S.; Sosebee, M.; Souza, M.; Spadafora, A. L.; Stampke, S.; Stephens, R.; Stevenson, M. L.; Stewart, D.; Stocker, F.; Stoyanova, D.; Stredde, H.; Streets, K.; Strovink, M.; Suhanov, A.; Taketani, A.; Tartaglia, M.; Taylor, J. D.; Teiger, J.; Theodosiou, G.; Thompson, J.; Tisserant, S.; Trippe, T. G.; Tuts, P. M.; Van Berg, R.; Vaz, M.; Vishwanath, P. R.; Volkov, A.; Vorobiev, A.; Wahl, H. D.; Wang, D.-C.; Wang, L.-Z.; Weerts, H.; Wenzel, W. A.; White, A.; White, J. T.; Wightman, J.; Willis, S.; Wimpenny, S. J.; Wolf, Z.; Womersley, J.; Wood, D. R.; Xia, Y.; Xiao, D.; Xie, P.; Xu, H.; Yamada, R.; Yamin, P.; Yanagisawa, C.; Yang, J.; Yang, M.-J.; Yoshikawa, C.; Youssef, S.; Yu, J.; Zeller, R.; Zhang, S.; Zhou, Y. H.; Zhu, Q.; Zhu, Y.-S.; Zieminska, D.; Zieminski, A.; Zinchenko, A.; Zylberstejn, A.; DØ Collaboration

    1994-01-01

    The DØ detector is a large general purpose detector for the study of short-distance phenomena in high energy antiproton-proton collisions, now in operation at the Fermilab Tevatron collider. The detector focusses upon the detection of electrons, muons, jets and missing transverse momentum. We describe the design and performance of the major elements of the detector, including the tracking chambers, transition radiation detector, liquid argon calorimetry and muon detection. The associated electronics, triggering systems and data acquisition systems are presented. The global mechanical, high voltage, and experiment monitoring and control systems which support the detector are described. We also discuss the design and implementation of software and software support systems that are specific to DØ.

  4. Noble Gas Detectors

    CERN Document Server

    Aprile, Elena; Bolozdynya, Alexander I; Doke, Tadayoshi

    2006-01-01

    This book discusses the physical properties of noble fluids, operational principles of detectors based on these media, and the best technical solutions to the design of these detectors. Essential attention is given to detector technology: purification methods and monitoring of purity, information readout methods, electronics, detection of hard ultra-violet light emission, selection of materials, cryogenics etc.The book is mostly addressed to physicists and graduate students involved in the preparation of fundamental next generation experiments, nuclear engineers developing instrumentation

  5. ATLAS inner detector performance

    CERN Document Server

    Gadomski, S

    2001-01-01

    The ATLAS Inner Detector consists of three subsystems using different tracking detector technologies: silicon pixels, silicon strips and straw tubes. The combination gives ATLAS a robust, hermetic and efficient tracking system, able to reconstruct tracks at the highest foreseen LHC luminosities. The inner detector provides vertex and momentum measurements, electron identification and some $K/\\pi$ separation. Since last year the beam pipe of ATLAS was changed, causing a redesign of the first tracking layer and a deterioration of the impact parameter resolutions.

  6. LHCb Detector Performance

    CERN Document Server

    AUTHOR|(CDS)2075808; Adeva, Bernardo; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Pessina, Gianluigi; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2015-01-01

    The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) at CERN. The experiment is designed for precision measurements of CP violation and rare decays of beauty and charm hadrons. In this paper the performance of the various LHCb sub-detectors and the trigger system are described, using data taken from 2010 to 2012. It is shown that the design criteria of the experiment have been met. The excellent performance of the detector has allowed the LHCb collaboration to publish a wide range of physics results, demonstrating LHCb's unique role, both as a heavy flavour experiment and as a general purpose detector in the forward region.

  7. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  8. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  9. Photocapacitive MIS infrared detectors

    Science.gov (United States)

    Sher, A.; Lu, S. S.-M.; Moriarty, J. A.; Crouch, R. K.; Miller, W. E.

    1978-01-01

    A new class of room-temperature infrared detectors has been developed through use of metal-insulator-semiconductor (MIS) or metal-insulator-semiconductor-insulator-metal (MISIM) slabs. The detectors, which have been fabricated from Si, Ge and GaAs, rely for operation on the electrical capacitance variations induced by modulated incident radiation. The peak detectivity for a 1000-A Si MISIM detector is comparable to that of a conventional Si detector functioning in the photovoltaic mode. Optimization of the photocapacitive-mode detection sensitivity is discussed.

  10. ALICE Photon Multiplicity Detector

    CERN Multimedia

    Nayak, T

    2013-01-01

    Photon Multiplicity Detector (PMD) measures the multiplicity and spatial distribution of photons in the forward region of ALICE on a event-by-event basis. PMD is a pre-shower detector having fine granularity and full azimuthal coverage in the pseudo-rapidity region 2.3 < η < 3.9.

  11. Detector Systems at CLIC

    CERN Document Server

    Simon, Frank

    2011-01-01

    The Compact Linear Collider CLIC is designed to deliver e+e- collisions at a center of mass energy of up to 3 TeV. The detector systems at this collider have to provide highly efficient tracking and excellent jet energy resolution and hermeticity for multi-TeV final states with multiple jets and leptons. In addition, the detector systems have to be capable of distinguishing physics events from large beam-induced background at a crossing frequency of 2 GHz. Like for the detector concepts at the ILC, CLIC detectors are based on event reconstruction using particle flow algorithms. The two detector concepts for the ILC, ILD and SID, were adapted for CLIC using calorimeters with dense absorbers limiting leakage through increased compactness, as well as modified forward and vertex detector geometries and precise time stamping to cope with increased background levels. The overall detector concepts for CLIC are presented, with particular emphasis on the main detector and engineering challenges, such as: the ultra-thi...

  12. ALICE Silicon Strip Detector

    CERN Multimedia

    Nooren, G

    2013-01-01

    The Silicon Strip Detector (SSD) constitutes the two outermost layers of the Inner Tracking System (ITS) of the ALICE Experiment. The SSD plays a crucial role in the tracking of the particles produced in the collisions connecting the tracks from the external detectors (Time Projection Chamber) to the ITS. The SSD also contributes to the particle identification through the measurement of their energy loss.

  13. CMS Detector Posters

    CERN Multimedia

    2016-01-01

    CMS Detector posters (produced in 2000): CMS installation CMS collaboration From the Big Bang to Stars LHC Magnetic Field Magnet System Trackering System Tracker Electronics Calorimetry Eletromagnetic Calorimeter Hadronic Calorimeter Muon System Muon Detectors Trigger and data aquisition (DAQ) ECAL posters (produced in 2010, FR & EN): CMS ECAL CMS ECAL-Supermodule cooling and mechatronics CMS ECAL-Supermodule assembly

  14. Pixel detector readout chip

    CERN Multimedia

    1991-01-01

    Close-up of a pixel detector readout chip. The photograph shows an aera of 1 mm x 2 mm containing 12 separate readout channels. The entire chip contains 1000 readout channels (around 80 000 transistors) covering a sensitive area of 8 mm x 5 mm. The chip has been mounted on a silicon detector to detect high energy particles.

  15. The LDC detector concept

    Indian Academy of Sciences (India)

    Ties Behnke; LDC Concept Group

    2007-11-01

    In preparation of the experimental program at the international linear collider (ILC), the large detector concept (LDC) is being developed. The main points of the LDC are a large volume gaseous tracking system, combined with high precision vertex detector and an extremely granular calorimeter. The main design force behind the LDC is the particle flow concept.

  16. Introduction to detectors

    CERN Document Server

    Walenta, Albert H

    1995-01-01

    Concepts for momentum measurements,particle identification and energy measurements (calorimeters) as well for imaging applications in medecine, biology and industry (non destructive testing) will be put into relation to the specific detection princip In particular the resolution for position, time, energy and intensity measurement and the efficiency will be discussed. Signal extraction,electronic signal processing and principles of information capture will close the logic circle to the input : the radiation properties.The lecture will provide some sources for data tables and small demonstration computer programs f The basic detector physics as interaction of radiation with matter, information transport via free charges,photons and phonons and the signal formation will be presented in some depth with emphasis on the influence on specific parameters for detector The lecture will cover the most popular detector principles, gas detectors (ion chambers,MPWC's and MSGC's), semiconductor detectors scintillators and ...

  17. Nanomechanical resonance detector

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, Jeffrey C; Zettl, Alexander K

    2013-10-29

    An embodiment of a nanomechanical frequency detector includes a support structure and a plurality of elongated nanostructures coupled to the support structure. Each of the elongated nanostructures has a particular resonant frequency. The plurality of elongated nanostructures has a range of resonant frequencies. An embodiment of a method of identifying an object includes introducing the object to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the object. An embodiment of a method of identifying a molecular species of the present invention includes introducing the molecular species to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the molecular species.

  18. The PERDaix detector

    Energy Technology Data Exchange (ETDEWEB)

    Bachlechner, Andreas; Beischer, Bastian; Greim, Roman [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany); Kirn, Thomas, E-mail: kirn@physik.rwth-aachen.de [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany); Mai, Carsten; Yearwood, Gregorio Roper; Schael, Stefan; Schug, David; Tholen, Heiner; Wienkenhoever, Jens [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany)

    2012-12-11

    The PERDaix (Proton Electron Radiation Detector Aix-la-Chapelle) detector is designed to measure charged particles in cosmic rays. It can distinguish particle species up to 5 GV rigidity. PERDaix was flown on the BEXUS-11 balloon on 23rd November 2010. The detector has the dimensions of 246 Multiplication-Sign 400 Multiplication-Sign 859 mm{sup 3}, a geometrical acceptance of 32 cm{sup 2}sr, a low weight of 40 kg and a low power consumption of 60 W. The spectrometer consists of a time-of-flight system, a scintillating fiber tracking detector, a permanent magnet and a transition radiation detector. Silicon photomultipliers are used as photodetectors in the time-of-flight and the tracker system.

  19. The PERDaix detector

    Science.gov (United States)

    Bachlechner, Andreas; Beischer, Bastian; Greim, Roman; Kirn, Thomas; Mai, Carsten; Yearwood, Gregorio Roper; Schael, Stefan; Schug, David; Tholen, Heiner; Wienkenhöver, Jens

    2012-12-01

    The PERDaix (Proton Electron Radiation Detector Aix-la-Chapelle) detector is designed to measure charged particles in cosmic rays. It can distinguish particle species up to 5 GV rigidity. PERDaix was flown on the BEXUS-11 balloon on 23rd November 2010. The detector has the dimensions of 246×400×859 mm3, a geometrical acceptance of 32 cm2sr, a low weight of 40 kg and a low power consumption of 60 W. The spectrometer consists of a time-of-flight system, a scintillating fiber tracking detector, a permanent magnet and a transition radiation detector. Silicon photomultipliers are used as photodetectors in the time-of-flight and the tracker system.

  20. ATLAS ITk Pixel detector

    CERN Document Server

    Gemme, Claudia; The ATLAS collaboration

    2016-01-01

    The high luminosity upgrade of the LHC (HL-LHC) in 2026 will provide new challenge to the ATLAS tracker. The current inner detector will be replaced with a whole silicon tracker which will consist of a five barrel layer Pixel detector surrounded by a four barrel layer Strip detector. The expected high radiation level are requiring the development of upgraded silicon sensors as well as new a front-end chip. The dense tracking environment will require finer granularity detectors. The data rates will require new technologies for high bandwidth data transmission and handling. The current status of the HL-LHC ATLA Pixel detector developments as well as the various layout options will be reviewed.

  1. Seasonal and interannual variability of sedimentation and organic matter distribution in the Buor Khaya Gulf – the primary recipient of input from Lena River and coastal erosion in the SE Laptev Sea

    Directory of Open Access Journals (Sweden)

    A. N. Charkin

    2011-02-01

    Full Text Available Climate warming is amplified in the land-sea system of the East Siberian Arctic, which also holds large pools of vulnerable carbon in permafrost. This coastal area is strongly influenced by sediment and carbon transport from both its large rivers and extensive erosion of Pleistocene permafrost along its coastline. This study is investigating the coastal fate of the sediment and organic carbon delivered to the Buor-Khaya Gulf, which is the first recipient of the 16 overwhelming fluvial discharge from the Lena River and is additionally receiving large input from extensive erosion of the coastal ice-complex (permafrost a.k.a. Yedoma; loess soil with high organic carbon content. Both water column suspended particulate matter (SPM and surface sediments were sampled at about 250 oceanographic stations in the Gulf in this multiyear effort, including one winter campaign, and analyzed for the distribution and sorting of sediment size, organic carbon content, and stable carbon isotope signals. The composition of the surface sediment suggests an overwhelmingly terrestrial contribution from both river and coastal erosion.

    Based on data collected during several years in the period 2000–2008, two different sedimentation regimes were revealed for the Buor-Khaya Gulf, the relative importance of each at a given time depend on hydrometeorological conditions, the Lena River water discharge and sea-ice regime: Type 1 erosion-accumulation and Type 2 accumulation.

    The Type 1 erosion-accumulation sedimentation regime is typical (2000–2006 for the ice-free period of the year (here considered in detail for August 2005. Under such conditions terrigenous sources of suspended particulate matter (SPM and particulate organic carbon (POC stem predominantly from river discharge, thermal erosion of coastal ice-complex and remobilized bottom sediments. The Type 2 accumulation sedimentation regime develops under ice

  2. pp-Solar Neutrino Spectroscopy: Return of the Indium Detector

    OpenAIRE

    2001-01-01

    A new indium-loaded liquid scintillator (LS) with up to 15wt% In and high light output promises a breakthrough in the 25y old proposal for observing pp solar neutrinos (nue) by tagged nue capture in 115In. Intense background from the natural beta-decay of In, the single obstacle blocking this project till now, can be reduced by more than x100 with the new In-LS. Only non-In background remains, dramatically relaxing design criteria. Eight tons of In yields ~400 pp nue/y after analysis cuts. Wi...

  3. The HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Laboratory of Physics; Aschenauer, E.C. [DESY, Zeuthen (Germany); Belostotski, S. [B.P. Konstantinov Petersburg Nuclear Physics Insitute, Gatchina (Russian Federation)] [and others; Collaboration: HERMES Recoil Detector Group

    2013-02-15

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  4. Detectors for Tomorrow's Instruments

    Science.gov (United States)

    Moseley, Harvey

    2009-01-01

    Cryogenically cooled superconducting detectors have become essential tools for a wide range of measurement applications, ranging from quantum limited heterodyne detection in the millimeter range to direct searches for dark matter with superconducting phonon detectors operating at 20 mK. Superconducting detectors have several fundamental and practical advantages which have resulted in their rapid adoption by experimenters. Their excellent performance arises in part from reductions in noise resulting from their low operating temperatures, but unique superconducting properties provide a wide range of mechanisms for detection. For example, the steep dependence of resistance with temperature on the superconductor/normal transition provides a sensitive thermometer for calorimetric and bolometric applications. Parametric changes in the properties of superconducting resonators provides a mechanism for high sensitivity detection of submillimeter photons. From a practical point of view, the use of superconducting detectors has grown rapidly because many of these devices couple well to SQUID amplifiers, which are easily integrated with the detectors. These SQUID-based amplifiers and multiplexers have matured with the detectors; they are convenient to use, and have excellent noise performance. The first generation of fully integrated large scale superconducting detection systems are now being deployed. I will discuss the prospects for a new generation of instruments designed to take full advantage of the revolution in detector technology.

  5. The Belle II Detector

    Science.gov (United States)

    Piilonen, Leo; Belle Collaboration, II

    2017-01-01

    The Belle II detector is now under construction at the KEK laboratory in Japan. This project represents a substantial upgrade of the Belle detector (and the KEKB accelerator). The Belle II experiment will record 50 ab-1 of data, a factor of 50 more than that recorded by Belle. This large data set, combined with the low backgrounds and high trigger efficiencies characteristic of an e+e- experiment, should provide unprecedented sensitivity to new physics signatures in B and D meson decays, and in τ lepton decays. The detector comprises many forefront subsystems. The vertex detector consists of two inner layers of silicon DEPFET pixels and four outer layers of double-sided silicon strips. These layers surround a beryllium beam pipe having a radius of only 10 mm. Outside of the vertex detector is a large-radius, small-cell drift chamber, an ``imaging time-of-propagation'' detector based on Cerenkov radiation for particle identification, and scintillating fibers and resistive plate chambers used to identify muons. The detector will begin commissioning in 2017.

  6. ATLAS Detector Interface Group

    CERN Multimedia

    Mapelli, L

    Originally organised as a sub-system in the DAQ/EF-1 Prototype Project, the Detector Interface Group (DIG) was an information exchange channel between the Detector systems and the Data Acquisition to provide critical detector information for prototype design and detector integration. After the reorganisation of the Trigger/DAQ Project and of Technical Coordination, the necessity to provide an adequate context for integration of detectors with the Trigger and DAQ lead to organisation of the DIG as one of the activities of Technical Coordination. Such an organisation emphasises the ATLAS wide coordination of the Trigger and DAQ exploitation aspects, which go beyond the domain of the Trigger/DAQ project itself. As part of Technical Coordination, the DIG provides the natural environment for the common work of Trigger/DAQ and detector experts. A DIG forum for a wide discussion of all the detector and Trigger/DAQ integration issues. A more restricted DIG group for the practical organisation and implementation o...

  7. Detectors - Electronics; Detecteurs - Electronique

    Energy Technology Data Exchange (ETDEWEB)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France)

    1998-04-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X {yields} e{sup -} converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the {sup 3}He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  8. The HOTWAXS detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E.; Derbyshire, G.E. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Diakun, G. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Duxbury, D.M. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom)], E-mail: d.m.duxbury@rl.ac.uk; Fairclough, J.P.A. [Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF (United Kingdom); Harvey, I.; Helsby, W.I. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Lipp, J.D.; Marsh, A.S.; Salisbury, J. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Sankar, G. [Royal Institution of GB, 21 Albemarle Street, London W1S 4BS (United Kingdom); Spill, E.J.; Stephenson, R. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Terrill, N.J. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2007-10-11

    The development and testing of the HOTWAXS position-sensitive X-ray detector for Synchrotron Radiation Sources is described. Funded from a facility development grant, the aim of the project was to produce a high counting rate, parallax-free photon counting detector to be used in the combined studies of X-ray absorption fine structure and X-ray diffraction (XAFS/XRD), and also in the technique of small angle and wide angle X-ray scattering (SAXS/WAXS). The detector system is described together with results of experiments carried out at the Daresbury Laboratory Synchrotron Radiation Source.

  9. Performance of GLD detector

    Indian Academy of Sciences (India)

    T Yoshioka

    2007-12-01

    Most of the important physics processes to be studied in the international linear collider (ILC) experiment have multi-jets in the final state. In order to achieve better jet energy resolution, the so-called particle flow algorithm (PFA) will be employed and there is a general consensus that PFA derives overall ILC detector design. Four detector concepts for the ILC experiment have been proposed so far in the world; the GLD detector that has a large inner calorimeter radius, which is considered to have an advantage for a PFA, is one of them. In this paper, general scheme and performance of the GLD-PFA will be presented.

  10. The Silicon Cube detector

    Energy Technology Data Exchange (ETDEWEB)

    Matea, I.; Adimi, N. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Blank, B. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France)], E-mail: blank@cenbg.in2p3.fr; Canchel, G.; Giovinazzo, J. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Borge, M.J.G.; Dominguez-Reyes, R.; Tengblad, O. [Insto. Estructura de la Materia, CSIC, Serrano 113bis, E-28006 Madrid (Spain); Thomas, J.-C. [GANIL, CEA/DSM - CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 5 (France)

    2009-08-21

    A new experimental device, the Silicon Cube detector, consisting of six double-sided silicon strip detectors placed in a compact geometry was developed at CENBG. Having a very good angular coverage and high granularity, it allows simultaneous measurements of energy and angular distributions of charged particles emitted from unbound nuclear states. In addition, large-volume Germanium detectors can be placed close to the collection point of the radioactive species to be studied. The setup is ideally suited for isotope separation on-line (ISOL)-type experiments to study multi-particle emitters and was tested during an experiment at the low-energy beam line of SPIRAL at GANIL.

  11. ATLAS Inner Detector Alignment

    CERN Document Server

    Bocci, A

    2008-01-01

    The ATLAS experiment is a multi-purpose particle detector that will study high-energy particle collisions produced by the Large Hadron Collider at CERN. In order to achieve its physics goals, the ATLAS tracking requires that the positions of the silicon detector elements have to be known to a precision better than 10 μm. Several track-based alignment algorithms have been developed for the Inner Detector. An extensive validation has been performed with simulated events and real data coming from the ATLAS. Results from such validation are reported in this paper.

  12. Directional radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, Jonathan L.

    2017-09-12

    Directional radiation detectors and systems, methods, and computer-readable media for using directional radiation detectors to locate a radiation source are provided herein. A directional radiation detector includes a radiation sensor. A radiation attenuator partially surrounds the radiation sensor and defines an aperture through which incident radiation is received by the radiation sensor. The aperture is positioned such that when incident radiation is received directly through the aperture and by the radiation sensor, a source of the incident radiation is located within a solid angle defined by the aperture. The radiation sensor senses at least one of alpha particles, beta particles, gamma particles, or neutrons.

  13. Novel Photo-Detectors and Photo-Detector Systems

    OpenAIRE

    Danilov, M.

    2008-01-01

    Recent developments in photo-detectors and photo-detector systems are reviewed. The main emphasis is made on Silicon Photo-Multipliers (SiPM) - novel and very attractive photo-detectors. Their main features are described. Properties of detectors manufactured by different producers are compared. Different applications are discussed including calorimeters, muon detection, tracking, Cherenkov light detection, and time of flight measurements.

  14. Infrared Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The end goal of this project is to develop proof-of-concept infrared detectors which can be integrated in future infrared instruments engaged in remote...

  15. ALICE Forward Multiplicity Detector

    CERN Multimedia

    Christensen, C

    2013-01-01

    The Forward Multiplicity Detector (FMD) extends the coverage for multiplicity of charge particles into the forward regions - giving ALICE the widest coverage of the 4 LHC experiments for these measurements.

  16. OPAL detector electromagnetic calorimeter

    CERN Multimedia

    1988-01-01

    Half of the electromagnetic calorimeter of the OPAL detector is seen in this photo. This calorimeter consists of 4720 blocks of lead glass. It was used to detect and measure the energy of photons, electrons and positrons by absorbing them.

  17. The LUX Prototype Detector

    CERN Document Server

    Akerib, D S; Bedikian, S; Bernstein, A; Bolozdynya, A; Bradley, A; Cahn, S; Carr, D; Chapman, J J; Clark, K; Classen, T; Curioni, A; Dahl, C E; Dazeley, S; deViveiros, L; Dragowsky, M; Druszkiewicz, E; Fiorucci, S; Gaitskell, R J; Hall, C; Faham, C; Holbrook, B; Kastens, L; Kazkaz, K; Kwong, J; Lander, R; Leonard, D; Malling, D; Mannino, R; McKinsey, D N; Mei, D; Mock, J; Morii, M; Nikkel, J; Phelps, P; Shutt, T; Skulski, W; Sorensen, P; Spaans, J; Steigler, T; Svoboda, R; Sweany, M; Thomson, J; Tripathi, M; Walsh, N; Webb, R; White, J; Wolfs, F L H; Woods, M; Zhang, C

    2012-01-01

    The LUX (Large Underground Xenon) detector is a two-phase xenon Time Projection Chamber (TPC) designed to search for WIMP-nucleon dark matter interactions. As with all noble element detectors, continuous purification of the detector medium is essential to produce a large ($>$1ms) electron lifetime; this is necessary for efficient measurement of the electron signal which in turn is essential for achieving robust discrimination of signal from background events. In this paper we describe the development of a novel purification system deployed in a prototype detector. The results from the operation of this prototype indicated heat exchange with an efficiency above 94% up to a flow rate of 42 slpm, allowing for an electron drift length greater than 1 meter to be achieved in approximately two days and sustained for the duration of the testing period.

  18. The CLIC Detector Concept

    CERN Document Server

    Pitters, Florian Michael

    2016-01-01

    CLIC is a concept for a future linear collider that would provide e+e- collisions at up to 3 TeV. The physics aims require a detector system with excellent jet energy and track momentum resolution, highly efficient flavour-tagging and lepton identification capabilities, full geometrical coverage extending to low polar angles and timing information in the order of nanoseconds to reject beam-induced background. To deal with those requirements, an extensive R&D programme is in place to overcome current technological limits. The CLIC detector concept includes a low-mass all-silicon vertex and tracking detector system and fine-grained calorimeters designed for particle flow analysis techniques, surrounded by a 4 T solenoid magnet. An overview of the requirements and design optimisations for the CLIC detector concept is presented.

  19. Hybrid photon detectors

    CERN Document Server

    D'Ambrosio, C

    2003-01-01

    Hybrid photon detectors detect light via vacuum photocathodes and accelerate the emitted photoelectrons by an electric field towards inversely polarized silicon anodes, where they are absorbed, thus producing electron-hole pairs. These, in turn, are collected and generate electronic signals on their ohmic contacts. This review first describes the characteristic properties of the main components of hybrid photon detectors: light entrance windows, photocathodes, and silicon anodes. Then, essential relations describing the trajectories of photoelectrons in electric and magnetic fields and their backscattering from the silicon anodes are derived. Depending on their anode configurations, three families of hybrid photon detectors are presented: hybrid photomultiplier tubes with single anodes for photon counting with high sensitivity and for gamma spectroscopy; multi-anode photon detector tubes with anodes subdivided into square or hexagonal pads for position-sensitive photon detection; imaging silicon pixel array t...

  20. GRAVITY detector systems

    Science.gov (United States)

    Mehrgan, Leander H.; Finger, Gert; Eisenhauer, Frank; Panduro, Johana

    2016-08-01

    GRAVITY is a second generation instrument for the VLT Interferometer, designed for high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the K-band. It will combine the AO corrected beams of the four VLT telescopes. In total, the GRAVITY instrument uses five eAPD detectors four for the infrared wavefront sensors of each telescope and one for the fringe tracker. In addition two Hawaii2RG arrays are installed, one for the acquisition camera and one for the spectrometer. The SAPHIRA eAPD array is a newly developed near-infrared detector with sub-electron noise performance at frame rates > 1Kfps. For all seven detectors the ESO common controller, NGC, is used. This paper presents an overview and comparison of GRAVITY detector systems and their final performances at the telescope

  1. Pocked surface neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas (Whitmore Lake, MI); Klann, Raymond (Bolingbrook, IL)

    2003-04-08

    The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

  2. Europe plans megaton detector

    CERN Multimedia

    Cartlidge, Edwin

    2004-01-01

    A group of French and Italian particle physicists hopes to carry on the long tradition of building large underground detectors by constructing a device deep under the Alps containing a million tonnes of extremely pure water.

  3. The pixelated detector

    CERN Multimedia

    Sutton, C

    1990-01-01

    "Collecting data as patterns of light or subatomic particles is vitally important in all the sciences. The new generation of solid-state detectors called pixel devices could transform experimental research at all levels" (4 pages).

  4. Improved CO [lidar detector

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, P.L.; Busch, G.E.; Thompson, D.C.; Remelius, D.K.; Wells, F.D.

    1999-07-18

    A high sensitivity, CO{sub 2} lidar detector, based on recent advances in ultra-low noise, readout integrated circuits (ROIC), is being developed. This detector will combine a high speed, low noise focal plane array (FPA) with a dispersive grating spectrometer. The spectrometer will filter the large background flux, thereby reducing the limiting background photon shot noise. In order to achieve the desired low noise levels, the HgCdTe FPA will be cooled to {approximately}50K. High speed, short pulse operation of the lidar system should enable the detector to operate with the order of a few noise electrons in the combined detector/ ROIC output. Current receiver design concepts will be presented, along with their expected noise performance.

  5. Detector Control System for the ATLAS Forward Proton detector

    CERN Document Server

    Czekierda, Sabina; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) is a forward detector using a Roman Pot technique, recently installed in the LHC tunnel. It is aiming at registering protons that were diffractively or electromagnetically scattered in soft and hard processes. Infrastructure of the detector consists of hardware placed both in the tunnel and in the control room USA15 (about 330 meters from the Roman Pots). AFP detector, like the other detectors of the ATLAS experiment, uses the Detector Control System (DCS) to supervise the detector and to ensure its safe and coherent operation, since the incorrect detector performance may influence the physics results. The DCS continuously monitors the detector parameters, subset of which is stored in data bases. Crucial parameters are guarded by alarm system. A detector representation as a hierarchical tree-like structure of well-defined subsystems built with the use of the Finite State Machine (FSM) toolkit allows for overall detector operation and visualization. Every node in the hierarchy is...

  6. The AMANDA Neutrino Detector

    Energy Technology Data Exchange (ETDEWEB)

    Wischnewski, R.; Andres, E.; Askebjer, P.; Barwick, S.; Bay, R.; Bergstroem, L.; Biron, A.; Booth, J.; Botner, O.; Bouchta, A.; Carius, S.; Carlson, M.; Chinowsky, W.; Chirkin, D.; Cowen, D.; Costa, C.; Dalberg, E.; Deyoung, T.; Edsjo, J.; Ekstroem, P.; Goobar, A.; Gray, L.; Hallgren, A.; Halzen, F.; Hardtke, R.; He, Y.; Hill, G.; Hulth, P.; Hundertmark, S.; Jacobsen, J.; Kandhadai, V.; Karle, A.; Kim, J.; Leich, H.; Leuthold, M.; Lindahl, P.; Liss, T.; Liubarsky, I.; Loaiza, P.; LOwder, D.; Marciniewski, P.; Miller, T.; Miocinovic, P.; Mock, P.; Morse, R.; Newcomer, M.; Niessen, P.; Nygren, D.; Perez de los Heros, C.; Porrata, R.; Price, P.; Przybylski, G.; Rhode, W.; Richter, S.; Rodriguez, J.; Romenesko, P.; Ross, D.; Rubinstein, H.; Schmidt, T.; Schneider, E.; Schwarz, R.; Schwendicke, U.; Smoot, G.; Solarz, M.; Sorin, V.; Spiering, C.; Steffen, P.; Stokstad, R.; Streicher, O.; Thollander, L.; Thon, T.; Tilav, S.; Walck, C.; Wiebusch, C.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S

    1999-03-01

    The first stage of the AMANDA High Energy Neutrino Detector at the South Pole, the 302 PMT array AMANDA-B with an expected effective area for TeV neutrinos of {approx} 10{sup 4} m{sup 2}, has been taking data since 1997. Progress with calibration, investigation of ice properties, as well as muon and neutrino data analysis are described. The next stage 20-string detector AMANDA-II with {approx}800 PMTs will be completed in spring 2000.

  7. Fiber optic detector

    Energy Technology Data Exchange (ETDEWEB)

    Partin, J.K.; Ward, T.E.; Grey, A.E.

    1990-12-31

    This invention is comprised of a portable fiber optic detector that senses the presence of specific target chemicals by exchanging the target chemical for a fluorescently-tagged antigen that is bound to an antibody which is in turn attached to an optical fiber. Replacing the fluorescently-tagged antigen reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

  8. Phi factory detector requirements

    Energy Technology Data Exchange (ETDEWEB)

    Arisaka, K.; Atac, M.; Berg, R.; Buchanan, C.; Calvette, M.; Khazin, B.; Kinoshita, K.; Muller, T.; Ohshima, T.; Olsen, S.; Park, J.; Santoni, C.; Shirai, J.; Solodov, E.; Thompson, J.; Triggiani, G.; Ueno, K.; Yamamoto, H.; Detector and Simulation Working Group

    1991-08-01

    We identify the experimental problems and the conditions required for successful phi-factory operation, and show the range of detector parameters which, in conjunction with different machine designs, may meet these conditions. We started by considering, comparing and criticizing the Italian and Novosibirsk designs. With this discussion as a background, we defined the apparent experimental problems and detector constraints. In this article we summarize our understanding. (orig./HSI).

  9. Modelling semiconductor pixel detectors

    CERN Document Server

    Mathieson, K

    2001-01-01

    expected after 200 ps in most cases. The effect of reducing the charge carrier lifetime and examining the charge collection efficiency has been utilised to explore how these detectors would respond in a harsh radiation environment. It is predicted that over critical carrier lifetimes (10 ps to 0.1 ns) an improvement of 40 % over conventional detectors can be expected. This also has positive implications for fabricating detectors, in this geometry, from materials which might otherwise be considered substandard. An analysis of charge transport in CdZnTe pixel detectors has been performed. The analysis starts with simulation studies into the formation of contacts and their influence on the internal electric field of planar detectors. The models include a number of well known defect states and these are balanced to give an agreement with a typical experimental I-V curve. The charge transport study extends to the development of a method for studying the effect of charge sharing in highly pixellated detectors. The ...

  10. Gamma ray detector modules

    Science.gov (United States)

    Capote, M. Albert (Inventor); Lenos, Howard A. (Inventor)

    2009-01-01

    A radiation detector assembly has a semiconductor detector array substrate of CdZnTe or CdTe, having a plurality of detector cell pads on a first surface thereof, the pads having a contact metallization and a solder barrier metallization. An interposer card has planar dimensions no larger than planar dimensions of the semiconductor detector array substrate, a plurality of interconnect pads on a first surface thereof, at least one readout semiconductor chip and at least one connector on a second surface thereof, each having planar dimensions no larger than the planar dimensions of the interposer card. Solder columns extend from contacts on the interposer first surface to the plurality of pads on the semiconductor detector array substrate first surface, the solder columns having at least one solder having a melting point or liquidus less than 120 degrees C. An encapsulant is disposed between the interposer circuit card first surface and the semiconductor detector array substrate first surface, encapsulating the solder columns, the encapsulant curing at a temperature no greater than 120 degrees C.

  11. ATLAS Inner Detector (Pixel Detector and Silicon Tracker)

    CERN Multimedia

    ATLAS Outreach

    2006-01-01

    To raise awareness of the basic functions of the Pixel Detector and Silicon Tracker in the ATLAS detector on the LHC at CERN. This colorful 3D animation is an excerpt from the film "ATLAS-Episode II, The Particles Strike Back." Shot with a bug's eye view of the inside of the detector. The viewer is taken on a tour of the inner workings of the detector, seeing critical pieces of the detector and hearing short explanations of how each works.

  12. Detectors on the drawing board

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    Linear collider detector developers inside and outside CERN are tackling the next generation of detector technology. While their focus has centred on high-energy linear collider detectors, their innovative concepts and designs will be applicable to any future detector.   A simulated event display in one of the new generation detectors. “While the LHC experiments remain the pinnacle of detector technology, you may be surprised to realise that the design and expertise behind them is well over 10 years old,” says Lucie Linssen, CERN’s Linear Collider Detector (LCD) project manager whose group is pushing the envelope of detector design. “The next generation of detectors will have to surpass the achievements of the LHC experiments. It’s not an easy task but, by observing detectors currently in operation and exploiting a decade’s worth of technological advancements, we’ve made meaningful progress.” The LCD team is curr...

  13. Detecting electron neutrinos from solar dark matter annihilation by JUNO

    CERN Document Server

    Guo, Wan-Lei

    2015-01-01

    We explore the electron neutrino signals from light dark matter (DM) annihilation in the Sun for the large liquid scintillator detector JUNO. In terms of the spectrum features of three typical DM annihilation channels $\\chi \\chi \\rightarrow \

  14. JUNO: a General Purpose Experiment for Neutrino Physics

    CERN Document Server

    Grassi, Marco

    2016-01-01

    JUNO is a 20 kt Liquid Scintillator Antineutrino Detector currently under construction in the south of China. This report reviews JUNO's physics programme related to all neutrino sources but reactor antineutrinos, namely neutrinos from supernova burst, solar neutrinos and geoneutrinos.

  15. The ZEUS microvertex detector

    CERN Document Server

    Garfagnini, A

    1999-01-01

    A new vertex detector for the ZEUS experiment at HERA will be installed during the 1999-2000 shutdown, for the high-luminosity runs of HERA. It will allow to reconstruct secondary vertex tracks, coming from the decay of long-lived particles with a lifetime of about 10 sup - sup 1 sup 2 s, and improve the global momentum resolution of the tracking system. The interaction region will be surrounded with single-sided silicon strip detectors, with capacitive charge division: three double layers in the central region (600 detectors), and 4 'wheels' in the forward region (112 silicon planes). Due to the high number of readout channels, 512 readout strips per silicon plane in the barrel region and 480 in the forward part, and the large coverage of the vertex detector (almost 1 m long), the front-end electronics has to be placed on top of the detectors and has to be radiation tolerant since doses up to 2 kGy are expected near the interaction region. The HELIX chip has been chosen as analog chip with a low-noise, charg...

  16. Nonequilibrium superconducting detectors

    Science.gov (United States)

    Cristiano, R.; Ejrnaes, M.; Esposito, E.; Lisitskyi, M. P.; Nappi, C.; Pagano, S.; Perez de Lara, D.

    2006-03-01

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  17. Nonequilibrium superconducting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, R [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Ejrnaes, M [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); INFN Sezione di Napoli, 80126 Naples (Italy); Esposito, E [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Lisitskyi, M P [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Nappi, C [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Pagano, S [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Saudi Arabia) (Italy); Perez de Lara, D [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy)

    2006-03-15

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  18. Detectors in Extreme Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Blaj, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carini, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carron, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Haller, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hart, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hasi, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Herrmann, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Kenney, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Segal, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tomada, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-06

    Free Electron Lasers opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120Hz pulses with 1012 - 1013 photons in 10 femtoseconds (billions of times brighter than the most powerful synchrotrons). This extreme detection environment raises unique challenges, from obvious to surprising. Radiation damage is a constant threat due to accidental exposure to insufficiently attenuated beam, focused beam and formation of ice crystals reflecting the beam onto the detector. Often high power optical lasers are also used (e.g., 25TW), increasing the risk of damage or impeding data acquisition through electromagnetic pulses (EMP). The sample can contaminate the detector surface or even produce shrapnel damage. Some experiments require ultra high vacuum (UHV) with strict design, surface contamination and cooling requirements - also for detectors. The setup is often changed between or during experiments with short turnaround times, risking mechanical and ESD damage, requiring work planning, training of operators and sometimes continuous participation of the LCLS Detector Group in the experiments. The detectors used most often at LCLS are CSPAD cameras for hard x-rays and pnCCDs for soft x-rays.

  19. OPERA: Electronic Detector

    CERN Document Server

    Jollet, C

    2010-01-01

    OPERA is an hybrid detector for the ni-tau appearance search in a direct way, and the Electronic Detectors (ED) have the crucial role of triggerring for the neutrino events and of localizing such an interaction inside the target. Another very important task of the ED is to identify the muon since only a correct matching of such a track with a track in the emulsion connected to the vertex of the event allows to reduce the charm background to the desired level. The ED, fully working since 2006, consist of a target tracker (scintillator strips) and a spectrometer (RPC and drift tubes). The different sub-detectors are de- scribed in the poster, as well as their performance both on Monte Carlo (MC) and real data.

  20. Transition Radiation Detectors

    CERN Document Server

    Andronic, A

    2012-01-01

    We review the basic features of transition radiation and how they are used for the design of modern Transition Radiation Detectors (TRD). The discussion will include the various realizations of radiators as well as a discussion of the detection media and aspects of detector construction. With regard to particle identification we assess the different methods for efficient discrimination of different particles and outline the methods for the quantification of this property. Since a number of comprehensive reviews already exist, we predominantly focus on the detectors currently operated at the LHC. To a lesser extent we also cover some other TRDs, which are planned or are currently being operated in balloon or space-borne astro-particle physics experiments.