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  1. The KATRIN Neutrino Mass Experiment

    NASA Astrophysics Data System (ADS)

    Parno, Diana; Katrin Collaboration

    2017-01-01

    While neutrino oscillation experiments have demonstrated that the particles have non-zero mass, the absolute neutrino mass scale is still unknown. The Karlsruhe Tritium Neutrino experiment (KATRIN) is designed to improve on previous laboratory limits by an order of magnitude, probing the effective neutrino mass with a sensitivity approaching 0.2 eV at 90% confidence via the kinematics of tritium beta decay. At the same time, KATRIN has the potential to scan for sterile neutrinos at eV and keV scales. After years of preparation, all major components are now on site and commissioning is underway. I will report on the current status of the experiment, including recent results and preparations for the introduction of tritium later this year. US participation in KATRIN is supported by the U.S. Department of Energy Office of Science, Office of Nuclear Physics under Award Number DE-FG02-97ER41020.

  2. Status of the neutrino mass experiment KATRIN

    SciTech Connect

    Bornschein, L.; Bornschein, B.; Sturm, M.; Roellig, M.; Priester, F.

    2015-03-15

    The most sensitive way to determine the neutrino mass scale without further assumptions is to measure the shape of a tritium beta spectrum near its kinematic end-point. Tritium is the nucleus of choice because of its low endpoint energy, superallowed decay and simple atomic structure. Within an international collaboration the Karlsruhe Tritium Neutrino experiment (KATRIN) is currently being built up at KIT. KATRIN will allow a model-independent measurement of the neutrino mass scale with an expected sensitivity of 0.2 eV/c{sup 2} (90% CL). KATRIN will use a source of ultrapure molecular tritium. This contribution presents the status of the KATRIN experiment, thereby focusing on its Calibration and Monitoring System (CMS), which is the last component being subject to research/development. After a brief overview of the KATRIN experiment in Section II the CMS is introduced in Section III. In Section IV the Beta Induced X-Ray Spectroscopy (BIXS) as method of choice to monitor the tritium activity of the KATRIN source is described and first results are presented.

  3. The KATRIN neutrino mass experiment

    NASA Astrophysics Data System (ADS)

    Wolf, Joachim; Katrin Collaboration

    2010-11-01

    The Karlsruhe Tritium Neutrino experiment (KATRIN) aims to determine the electron neutrino mass from tritium decay in a model-independent way, by a kinematic measurement of the energy of β-electrons. The unprecedented sensitivity of 0.2 eV/c2 will improve present limits by one order of magnitude. The decay electrons will originate from a 10 m long windowless gaseous tritium source. Super-conducting magnets will guide the electrons through a differential and cryogenic pumping section to the electro-static tandem spectrometer (MAG-E-filter), where the kinetic energy will be measured. The experiment is presently being built at the Forschungszentrum Karlsruhe by an international collaboration of more than 120 scientists. The largest component, the 1240 m3 main spectrometer, was delivered end of 2006 and first commissioning tests have been performed. This paper gives an overview of the goals and technological challenges of the experiment and reports on the progress in commissioning first major components. The start of first measurements is expected in 2012.

  4. Detecting sterile neutrinos with KATRIN like experiments

    SciTech Connect

    Riis, Anna Sejersen; Hannestad, Steen E-mail: sth@phys.au.dk

    2011-02-01

    A sterile neutrino with mass in the eV range, mixing with ν-bar {sub e}, is allowed and possibly even preferred by cosmology and oscillation experiments. If such eV-mass neutrinos exist they provide a much better target for direct detection in beta decay experiments than the active neutrinos which are expected to have sub-eV masses. Their relatively high mass would allow for an easy separation from the primary decay signal in experiments such as KATRIN.

  5. Focal-plane detector system for the KATRIN experiment

    DOE PAGES

    Amsbaugh, J. F.; Barrett, J.; Beglarian, A.; ...

    2015-01-09

    Here, the local plane detector system for the KArlsiuhe TRItium Neutrino (KATRIN) experiment consists of a multi-pixel silicon p-i-n-diode array, custom readout electronics, two superconducting solenoid magnets, an ultra high vacuum system, a high vacuum system, calibration and monitoring devices, a scintillating veto, and a custom data-acquisition system, It is designed to detect the low-energy electrons selected by the KATRIN main spectrometer. We describe the system and summarize its performance after its final installation.

  6. Commissioning of the vacuum system of the KATRIN Main Spectrometer

    NASA Astrophysics Data System (ADS)

    Arenz, M.; Babutzka, M.; Bahr, M.; Barrett, J. P.; Bauer, S.; Beck, M.; Beglarian, A.; Behrens, J.; Bergmann, T.; Besserer, U.; Blümer, J.; Bodine, L. I.; Bokeloh, K.; Bonn, J.; Bornschein, B.; Bornschein, L.; Büsch, S.; Burritt, T. H.; Chilingaryan, S.; Corona, T. J.; De Viveiros, L.; Doe, P. J.; Dragoun, O.; Drexlin, G.; Dyba, S.; Ebenhöch, S.; Eitel, K.; Ellinger, E.; Enomoto, S.; Erhard, M.; Eversheim, D.; Fedkevych, M.; Felden, A.; Fischer, S.; Formaggio, J. A.; Fränkle, F.; Furse, D.; Ghilea, M.; Gil, W.; Glück, F.; Gonzalez Ureña, A.; Görhardt, S.; Groh, S.; Grohmann, S.; Grössle, R.; Gumbsheimer, R.; Hackenjos, M.; Hannen, V.; Harms, F.; Haußmann, N.; Heizmann, F.; Helbing, K.; Herz, W.; Hickford, S.; Hilk, D.; Hillen, B.; Höhn, T.; Holzapfel, B.; Hötzel, M.; Howe, M. A.; Huber, A.; Jansen, A.; Kernert, N.; Kippenbrock, L.; Kleesiek, M.; Klein, M.; Kopmann, A.; Kosmider, A.; Kovalík, A.; Krasch, B.; Kraus, M.; Krause, H.; Krause, M.; Kuckert, L.; Kuffner, B.; La Cascio, L.; Lebeda, O.; Leiber, B.; Letnev, J.; Lobashev, V. M.; Lokhov, A.; Malcherek, E.; Mark, M.; Martin, E. L.; Mertens, S.; Mirz, S.; Monreal, B.; Müller, K.; Neuberger, M.; Neumann, H.; Niemes, S.; Noe, M.; Oblath, N. S.; Off, A.; Ortjohann, H.-W.; Osipowicz, A.; Otten, E.; Parno, D. S.; Plischke, P.; Poon, A. W. P.; Prall, M.; Priester, F.; Ranitzsch, P. C.-O.; Reich, J.; Rest, O.; Robertson, R. G. H.; Röllig, M.; Rosendahl, S.; Rupp, S.; Ryšavý, M.; Schlösser, K.; Schlösser, M.; Schönung, K.; Schrank, M.; Schwarz, J.; Seiler, W.; Seitz-Moskaliuk, H.; Sentkerestiová, J.; Skasyrskaya, A.; Slezák, M.; Špalek, A.; Steidl, M.; Steinbrink, N.; Sturm, M.; Suesser, M.; Telle, H. H.; Thümmler, T.; Titov, N.; Tkachev, I.; Trost, N.; Unru, A.; Valerius, K.; Vénos, D.; Vianden, R.; Vöcking, S.; Wall, B. L.; Wandkowsky, N.; Weber, M.; Weinheimer, C.; Weiss, C.; Welte, S.; Wendel, J.; Wierman, K. L.; Wilkerson, J. F.; Winzen, D.; Wolf, J.; Wüstling, S.; Zacher, M.; Zadoroghny, S.; Zbořil, M.

    2016-04-01

    The KATRIN experiment will probe the neutrino mass by measuring the β-electron energy spectrum near the endpoint of tritium β-decay. An integral energy analysis will be performed by an electro-static spectrometer (``Main Spectrometer''), an ultra-high vacuum vessel with a length of 23.2 m, a volume of 1240 m3, and a complex inner electrode system with about 120 000 individual parts. The strong magnetic field that guides the β-electrons is provided by super-conducting solenoids at both ends of the spectrometer. Its influence on turbo-molecular pumps and vacuum gauges had to be considered. A system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter strips has been deployed and was tested during the commissioning of the spectrometer. In this paper the configuration, the commissioning with bake-out at 300 °C, and the performance of this system are presented in detail. The vacuum system has to maintain a pressure in the 10-11 mbar range. It is demonstrated that the performance of the system is already close to these stringent functional requirements for the KATRIN experiment, which will start at the end of 2016.

  7. Commissioning of the vacuum system of the KATRIN Main Spectrometer

    DOE PAGES

    Arenz, M.; Babutzka, M.; Bahr, M.; ...

    2016-04-07

    The KATRIN experiment will probe the neutrino mass by measuring the β-electron energy spectrum near the endpoint of tritium β-decay. We performed an integral energy analysis by an electro-static spectrometer (``Main Spectrometer''), an ultra-high vacuum vessel with a length of 23.2 m, a volume of 1240 m3, and a complex inner electrode system with about 120 000 individual parts. The strong magnetic field that guides the β-electrons is provided by super-conducting solenoids at both ends of the spectrometer. Its influence on turbo-molecular pumps and vacuum gauges had to be considered. Furthermore, a system consisting of 6 turbo-molecular pumps and 3more » km of non-evaporable getter strips has been deployed and was tested during the commissioning of the spectrometer. In this paper the configuration, the commissioning with bake-out at 300 °C, and the performance of this system are presented in detail. The vacuum system has to maintain a pressure in the 10-11 mbar range. We demonstrated that the performance of the system is already close to these stringent functional requirements for the KATRIN experiment, which will start at the end of 2016.« less

  8. Commissioning of the vacuum system of the KATRIN Main Spectrometer

    SciTech Connect

    Arenz, M.; Babutzka, M.; Bahr, M.; Barrett, J. P.; Bauer, S.; Beck, M.; Beglarian, A.; Behrens, J.; Bergmann, T.; Besserer, U.; Blümer, J.; Bodine, L. I.; Bokeloh, K.; Bonn, J.; Bornschein, B.; Bornschein, L.; Büsch, S.; Burritt, T. H.; Chilingaryan, S.; Corona, T. J.; Viveiros, L. De; Doe, P. J.; Dragoun, O.; Drexlin, G.; Dyba, S.; Ebenhöch, S.; Eitel, K.; Ellinger, E.; Enomoto, S.; Erhard, M.; Eversheim, D.; Fedkevych, M.; Felden, A.; Fischer, S.; Formaggio, J. A.; Fränkle, F.; Furse, D.; Ghilea, M.; Gil, W.; Glück, F.; Ureña, A. Gonzalez; Görhardt, S.; Groh, S.; Grohmann, S.; Grössle, R.; Gumbsheimer, R.; Hackenjos, M.; Hannen, V.; Harms, F.; Haußmann, N.; Heizmann, F.; Helbing, K.; Herz, W.; Hickford, S.; Hilk, D.; Hillen, B.; Höhn, T.; Holzapfel, B.; Hötzel, M.; Howe, M. A.; Huber, A.; Jansen, A.; Kernert, N.; Kippenbrock, L.; Kleesiek, M.; Klein, M.; Kopmann, A.; Kosmider, A.; Kovalík, A.; Krasch, B.; Kraus, M.; Krause, H.; Krause, M.; Kuckert, L.; Kuffner, B.; Cascio, L. La; Lebeda, O.; Leiber, B.; Letnev, J.; Lobashev, V. M.; Lokhov, A.; Malcherek, E.; Mark, M.; Martin, E. L.; Mertens, S.; Mirz, S.; Monreal, B.; Müller, K.; Neuberger, M.; Neumann, H.; Niemes, S.; Noe, M.; Oblath, N. S.; Off, A.; Ortjohann, H. -W.; Osipowicz, A.; Otten, E.; Parno, D. S.; Plischke, P.; Poon, A. W. P.; Prall, M.; Priester, F.; Ranitzsch, P. C. -O.; Reich, J.; Rest, O.; Robertson, R. G. H.; Röllig, M.; Rosendahl, S.; Rupp, S.; Ryšavý, M.; Schlösser, K.; Schlösser, M.; Schönung, K.; Schrank, M.; Schwarz, J.; Seiler, W.; Seitz-Moskaliuk, H.; Sentkerestiová, J.; Skasyrskaya, A.; Slezák, M.; Špalek, A.; Steidl, M.; Steinbrink, N.; Sturm, M.; Suesser, M.; Telle, H. H.; Thümmler, T.; Titov, N.; Tkachev, I.; Trost, N.; Unru, A.; Valerius, K.; Vénos, D.; Vianden, R.; Vöcking, S.; Wall, B. L.; Wandkowsky, N.; Weber, M.; Weinheimer, C.; Weiss, C.; Welte, S.; Wendel, J.; Wierman, K. L.; Wilkerson, J. F.; Winzen, D.; Wolf, J.; Wüstling, S.; Zacher, M.; Zadoroghny, S.; Zbořil, M.

    2016-04-07

    The KATRIN experiment will probe the neutrino mass by measuring the β-electron energy spectrum near the endpoint of tritium β-decay. We performed an integral energy analysis by an electro-static spectrometer (``Main Spectrometer''), an ultra-high vacuum vessel with a length of 23.2 m, a volume of 1240 m3, and a complex inner electrode system with about 120 000 individual parts. The strong magnetic field that guides the β-electrons is provided by super-conducting solenoids at both ends of the spectrometer. Its influence on turbo-molecular pumps and vacuum gauges had to be considered. Furthermore, a system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter strips has been deployed and was tested during the commissioning of the spectrometer. In this paper the configuration, the commissioning with bake-out at 300 °C, and the performance of this system are presented in detail. The vacuum system has to maintain a pressure in the 10-11 mbar range. We demonstrated that the performance of the system is already close to these stringent functional requirements for the KATRIN experiment, which will start at the end of 2016.

  9. Introduction to direct neutrino mass measurements and KATRIN

    NASA Astrophysics Data System (ADS)

    Thümmler, T.; Katrin Collaboration

    2012-08-01

    The properties of neutrinos and especially their rest mass play an important role at the intersections of cosmology, particle physics and astroparticle physics. At present there are two complementary approaches to address this topic in laboratory experiments. The search for neutrinoless double beta decay probes whether neutrinos are Majorana particles and determines an effective neutrino mass value. On the other hand experiments such as MARE, KATRIN and the recently proposed Project 8 will investigate the spectral shape of β-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Here, because of neutrino flavour mixing, the neutrino mass appears as an average of all neutrino mass eigenstates contributing to the electron neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. It combines an ultra-luminous molecular windowless gaseous tritium source with an integrating high-resolution spectrometer of MAC-E filter type. It will investigate the neutrino rest mass with 0.2 eV/c (90% C.L.) sensitivity and allow β spectroscopy close to the T endpoint at 18.6 keV with unprecedented precision.

  10. Sterile neutrinos and right-handed currents in KATRIN

    NASA Astrophysics Data System (ADS)

    Barry, James; Heeck, Julian; Rodejohann, Werner

    2014-07-01

    Kurie-plot experiments allow for neutrino-mass measurements based on kinematics in an almost model-independent manner. A future tritium-based KATRIN-like experiment can be sensitive to light sterile neutrinos with masses below 18 keV, which are among the prime candidates for warm dark matter. Here we consider such keV neutrinos in left-right symmetric extensions, i.e. coupled to right-handed currents, which allow for an enhanced contribution to beta decay even for small active-sterile mixing, without violating astrophysical X-ray constraints. The modified spectral shape is in principle distinguishable from the standard contribution — especially for sterile neutrino masses below 9 keV, which can lead to a distinct peak. We compare the sensitivity to constraints from the LHC and neutrinoless double beta decay.

  11. Status and commissioning of the Karlsruhe tritium neutrino experiment KATRIN

    NASA Astrophysics Data System (ADS)

    Thuemmler, Thomas; Katrin Collaboration

    2013-10-01

    Neutrino properties, and especially the determination of the neutrino rest mass, play an important role at the intersections of cosmology, particle physics and astroparticle physics. At present there are two complementary approaches to address this topic in laboratory experiments. The search for neutrinoless double β decay probes whether neutrinos are Majorana particles and determines an effective neutrino mass value. Experiments based on single β decay investigate electrons close to their kinematic endpoint in order to determine the neutrino mass by a modelindependent method. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. Applying an ultra-luminous molecular windowless gaseous tritium source and an integrating high-resolution spectrometer of MAC-E filter type, it allows β spectroscopy close to the tritium endpoint with unprecedented precision and will reach a sensitivity of 200 meV/c2 (90% C.L.) on the neutrino mass.

  12. Deconvolution of the energy loss function of the KATRIN experiment

    NASA Astrophysics Data System (ADS)

    Hannen, V.; Heese, I.; Weinheimer, C.; Sejersen Riis, A.; Valerius, K.

    2017-03-01

    The KATRIN experiment aims at a direct and model independent determination of the neutrino mass with 0.2 eV/c2 sensitivity (at 90% C.L.) via a measurement of the endpoint region of the tritium beta-decay spectrum. The main components of the experiment are a windowless gaseous tritium source (WGTS), differential and cryogenic pumping sections and a tandem of a pre- and a main-spectrometer, applying the concept of magnetic adiabatic collimation with an electrostatic retardation potential to analyze the energy of beta decay electrons and to guide electrons passing the filter onto a segmented silicon PIN detector. One of the important systematic uncertainties of such an experiment are due to energy losses of β-decay electrons by elastic and inelastic scattering off tritium molecules within the source volume which alter the shape of the measured spectrum. To correct for these effects an independent measurement of the corresponding energy loss function is required. In this work we describe a deconvolution method to extract the energy loss function from measurements of the response function of the experiment at different column densities of the WGTS using a monoenergetic electron source.

  13. Measurement and reduction of low-level radon background in the KATRIN experiment

    SciTech Connect

    Fränkle, F. M.

    2013-08-08

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a next generation, model independent, large scale experiment to determine the mass of the electron anti-neutrino by investigating the kinematics of tritium beta decay with a sensitivity of 200 meV/c{sup 2}. The measurement setup consists of a high luminosity windowless gaseous molecular tritium source (WGTS), a differential and cryogenic pumped electron transport and tritium retention section, a tandem spectrometer section (pre-spectrometer and main spectrometer) for energy analysis, followed by a detector system for counting transmitted beta decay electrons. Measurements performed at the KATRIN pre-spectrometer test setup showed that the decay of radon (Rn) atoms in the volume of the KATRIN spectrometers is a major background source. Rn atoms from low-level radon emanation of materials inside the vacuum region of the KATRIN spectrometers are able to penetrate deep into the magnetic flux tube so that the alpha decay of Rn contributes to the background. Of particular importance are electrons emitted in processes accompanying the Rn alpha decay, such as shake-off, internal conversion of excited levels in the Rn daughter atoms and Auger electrons. Lowenergy electrons (< 100 eV) directly contribute to the background in the signal region. High-energy electrons can be stored magnetically inside the volume of the spectrometer and are able to create thousands of secondary electrons via subsequent ionization processes with residual gas molecules. In order to reduce the Rn induced background different active and passive counter measures were developed and tested. This proceeding will give an overview on Rn sources within the KATRIN spectrometer, describes how Rn decays inside the spectrometer produce background events at the detector and presents different counter measures to reduce the Rn induced background.

  14. Electron line shape and transmission function of the KATRIN monitor spectrometer

    SciTech Connect

    Slezák, M.

    2013-12-30

    Knowledge of the neutrino mass is of particular interest in modern neutrino physics. Besides the neutrinoless double beta decay and cosmological observation information about the neutrino mass is obtained from single beta decay by observing the shape of the electron spectrum near the endpoint. The KATRIN β decay experiment aims to push the limit on the effective electron antineutrino mass down to 0.2 eV/c{sup 2}. To reach this sensitivity several systematic effects have to be under control. One of them is the fluctuations of the absolute energy scale, which therefore has to be continuously monitored at very high precision. This paper shortly describes KATRIN, the technique for continuous monitoring of the absolute energy scale and recent improvements in analysis of the monitoring data.

  15. Tests of by-pass diodes at cryogenic temperatures for the KATRIN magnets

    SciTech Connect

    Gil, W.; Bolz, H.; Jansen, A.; Müller, K.; Steidl, M.; Hagedorn, D.

    2014-01-27

    The Karlsruhe Tritium Neutrino experiment (KATRIN) requires a series of superconducting solenoid magnets for guiding beta-electrons from the source to the detector. By-pass diodes will operate at liquid helium temperatures to protect the superconducting magnets and bus bars in case of quenches. The operation conditions of the by-pass diodes depend on the different magnet systems of KATRIN. Therefore, different diode stacks are designed with adequate copper heat sinks assuming adiabatic conditions. The by-pass diode stacks have been submitted to cold tests both at liquid nitrogen and liquid helium temperatures for checking operation conditions. This report presents the test set up and first results of the diode characteristics at 300 K and 77 K, as well as of endurance tests of the diode stacks at constant current load at 77 K and 4.2 K.

  16. Neutrinos secretly converting to lighter particles to please both KATRIN and the cosmos

    SciTech Connect

    Farzan, Yasaman; Hannestad, Steen E-mail: sth@phys.au.dk

    2016-02-01

    Within the framework of the Standard Model of particle physics and standard cosmology, observations of the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO) set stringent bounds on the sum of the masses of neutrinos. If these bounds are satisfied, the upcoming KATRIN experiment which is designed to probe neutrino mass down to ∼ 0.2 eV will observe only a null signal. We show that the bounds can be relaxed by introducing new interactions for the massive active neutrinos, making neutrino masses in the range observable by KATRIN compatible with cosmological bounds. Within this scenario, neutrinos convert to new stable light particles by resonant production of intermediate states around a temperature of T∼ keV in the early Universe, leading to a much less pronounced suppression of density fluctuations compared to the standard model.

  17. Reduction in cryptosporidiosis associated with introduction of enhanced filtration of drinking water at Loch Katrine, Scotland.

    PubMed

    Pollock, K G J; Young, D; Robertson, C; Ahmed, S; Ramsay, C N

    2014-01-01

    Previous evidence has suggested an association between cryptosporidiosis and consumption of unfiltered drinking water from Loch Katrine in Scotland. Before September 2007, the water was only micro-strained and chlorinated; however, since that time, coagulation and rapid gravity filtration have been installed. In order to determine risk factors associated with cryptosporidiosis, including drinking water, we analysed data on microbiologically confirmed cases of cryptosporidiosis from 2004 to 2010. We identified an association between the incidence of cryptosporidiosis and unfiltered Loch Katrine drinking water supplied to the home (odds ratio 1.86, 95% confidence interval 1.11-3.11, P = 0.019). However, while filtration appears to be associated with initially reduced rates of cryptosporidiosis, evidence suggests it may paradoxically make those consumers more susceptible to other transmission routes in the long-term. These findings support implementation of similar treatment for other unfiltered drinking-water supplies, as a means of reducing cryptosporidiosis associated with drinking water.

  18. Simulation of background from low-level tritium and radon emanation in the KATRIN spectrometers

    SciTech Connect

    Leiber, B.; Collaboration: KATRIN Collaboration

    2013-08-08

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a large-scale experiment for the model independent determination of the mass of electron anti-neutrinos with a sensitivity of 200 meV/c{sup 2}. It investigates the kinematics of electrons from tritium beta decay close to the endpoint of the energy spectrum at 18.6 keV. To achieve a good signal to background ratio at the endpoint, a low background rate below 10{sup −2} counts per second is required. The KATRIN setup thus consists of a high luminosity windowless gaseous tritium source (WGTS), a magnetic electron transport system with differential and cryogenic pumping for tritium retention, and electro-static retarding spectrometers (pre-spectrometer and main spectrometer) for energy analysis, followed by a segmented detector system for counting transmitted beta-electrons. A major source of background comes from magnetically trapped electrons in the main spectrometer (vacuum vessel: 1240 m{sup 3}, 10{sup −11} mbar) produced by nuclear decays in the magnetic flux tube of the spectrometer. Major contributions are expected from short-lived radon isotopes and tritium. Primary electrons, originating from these decays, can be trapped for hours, until having lost almost all their energy through inelastic scattering on residual gas particles. Depending on the initial energy of the primary electron, up to hundreds of low energetic secondary electrons can be produced. Leaving the spectrometer, these electrons will contribute to the background rate. This contribution describes results from simulations for the various background sources. Decays of {sup 219}Rn, emanating from the main vacuum pump, and tritium from the WGTS that reaches the spectrometers are expected to account for most of the background. As a result of the radon alpha decay, electrons are emitted through various processes, such as shake-off, internal conversion and the Auger deexcitations. The corresponding simulations were done using the KASSIOPEIA

  19. Next generation KATRIN high precision voltage divider for voltages up to 65kV

    NASA Astrophysics Data System (ADS)

    Bauer, S.; Berendes, R.; Hochschulz, F.; Ortjohann, H.-W.; Rosendahl, S.; Thümmler, T.; Schmidt, M.; Weinheimer, C.

    2013-10-01

    The KATRIN (KArlsruhe TRItium Neutrino) experiment aims to determine the mass of the electron antineutrino with a sensitivity of 200 meV by precisely measuring the electron spectrum of the tritium beta decay. This will be done by the use of a retarding spectrometer of the MAC-E-Filter type. To achieve the desired sensitivity the stability of the retarding potential of -18.6 kV has to be monitored with a precision of 3 ppm over at least two months. Since this is not feasible with commercial devices, two ppm-class high voltage dividers were developed, following the concept of the standard divider for DC voltages of up to 100 kV of the Physikalisch-Technische Bundesanstalt (PTB). In order to reach such high accuracies different effects have to be considered. The two most important ones are the temperature dependence of resistance and leakage currents, caused by insulators or corona discharges. For the second divider improvements were made concerning the high-precision resistors and the thermal design of the divider. The improved resistors are the result of a cooperation with the manufacturer. The design improvements, the investigation and the selection of the resistors, the built-in ripple probe and the calibrations at PTB will be reported here. The latter demonstrated a stability of about 0.1 ppm/month over a period of two years.

  20. 3 Neutrino mass experiments fit a strange 3 + 3 model, but will KATRIN reveal the model's unique 3-part signature?

    NASA Astrophysics Data System (ADS)

    Ehrlich, R.

    2016-12-01

    Evidence is presented in support of an unconventional 3 + 3 model of the neutrino mass eigenstates with specific m2 > 0 and m2 < 0 masses. The two large m2 > 0 masses of the model were originally suggested based on a SN 1987A analysis, and they were further supported by several dark matter fits. The new evidence for one of the m2 > 0 mass values comes from an analysis of published data from the three most precise tritium β - decay experiments. The KATRIN experiment by virtue of a unique 3-part signature should either confirm or reject the model in its entirety.

  1. Status of the KATRIN experiment and prospects to search for keV-mass sterile neutrinos in tritium β-decay

    SciTech Connect

    Mertens, Susanne

    2015-03-24

    In this contribution the current status and future perspectives of the Karlsruhe Tritium Neutrino (KATRIN) Experiment are presented. The prime goal of this single β-decay experiment is to probe the absolute neutrino mass scale with a sensitivity of 200 meV (90% CL). We discuss first results of the recent main spectrometer commissioning measurements, successfully verifying the spectrometer’s basic vacuum, transmission and background properties. We also discuss the prospects of making use of the KATRIN tritium source, to search for sterile neutrinos in the multi-keV mass range constituting a classical candidate for Warm Dark Matter. Due to the very high source luminosity, a statistical sensitivity down to active-sterile mixing angles of sin² θ < 1 · 10⁻⁷ (90% CL) could be reached.

  2. Status of the KATRIN experiment and prospects to search for keV-mass sterile neutrinos in tritium β-decay

    DOE PAGES

    Mertens, Susanne

    2015-03-24

    In this contribution the current status and future perspectives of the Karlsruhe Tritium Neutrino (KATRIN) Experiment are presented. The prime goal of this single β-decay experiment is to probe the absolute neutrino mass scale with a sensitivity of 200 meV (90% CL). We discuss first results of the recent main spectrometer commissioning measurements, successfully verifying the spectrometer’s basic vacuum, transmission and background properties. We also discuss the prospects of making use of the KATRIN tritium source, to search for sterile neutrinos in the multi-keV mass range constituting a classical candidate for Warm Dark Matter. Due to the very high sourcemore » luminosity, a statistical sensitivity down to active-sterile mixing angles of sin² θ < 1 · 10⁻⁷ (90% CL) could be reached.« less

  3. Impact of ADC non-linearities on the sensitivity to sterile keV neutrinos with a KATRIN-like experiment

    NASA Astrophysics Data System (ADS)

    Dolde, Kai; Mertens, Susanne; Radford, David; Bode, Tobias; Huber, Anton; Korzeczek, Marc; Lasserre, Thierry; Slezak, Martin

    2017-03-01

    ADC non-linearities are a major systematic effect in the search for keV-scale sterile neutrinos with tritium β-decay experiments like KATRIN. They can significantly distort the spectral shape and thereby obscure the tiny kink-like signature of a sterile neutrino. In this work we demonstrate various mitigation techniques to reduce the impact of ADC non-linearities on the tritium β-decay spectrum to a level of < ppm . The best results are achieved with a multi-pixel (≥104 pixels) detector using full waveform digitization. In this case, active-to-sterile mixing angles of the order of sin2 θ =10-7 would be accessible from the viewpoint of ADC non-linearities. With purely peak-sensing ADCs a comparable sensitivity could be reached with highly linear ADCs, sufficient non-linearity corrections or by increasing the number of pixels to ≥105 .

  4. Validation of 3D Code KATRIN For Fast Neutron Fluence Calculation of VVER-1000 Reactor Pressure Vessel by Ex-Vessel Measurements and Surveillance Specimens Results

    NASA Astrophysics Data System (ADS)

    Dzhalandinov, A.; Tsofin, V.; Kochkin, V.; Panferov, P.; Timofeev, A.; Reshetnikov, A.; Makhotin, D.; Erak, D.; Voloschenko, A.

    2016-02-01

    Usually the synthesis of two-dimensional and one-dimensional discrete ordinate calculations is used to evaluate neutron fluence on VVER-1000 reactor pressure vessel (RPV) for prognosis of radiation embrittlement. But there are some cases when this approach is not applicable. For example the latest projects of VVER-1000 have upgraded surveillance program. Containers with surveillance specimens are located on the inner surface of RPV with fast neutron flux maximum. Therefore, the synthesis approach is not suitable enough for calculation of local disturbance of neutron field in RPV inner surface behind the surveillance specimens because of their complicated and heterogeneous structure. In some cases the VVER-1000 core loading consists of fuel assemblies with different fuel height and the applicability of synthesis approach is also ambiguous for these fuel cycles. Also, the synthesis approach is not enough correct for the neutron fluence estimation at the RPV area above core top. Because of these reasons only the 3D neutron transport codes seem to be satisfactory for calculation of neutron fluence on the VVER-1000 RPV. The direct 3D calculations are also recommended by modern regulations.

  5. El Lenguaje de los Chicanos (The Language of Chicanos). Regional and Social Characteristics of Language Used by Mexican Americans.

    ERIC Educational Resources Information Center

    Hernandez-Chavez, Eduardo, Ed.; And Others

    The following articles are included in this anthology on Chicano speech: (1) "Mexican Spanish," D.N. Cardenas; (2) "The Archaic and the Modern in the Spanish of New Mexico," J. Ornstein; (3) "Problemas Lexicograficos del Espanol del Sudoeste," A.M. Espinosa, Jr.; (4) "Associative Interference in New Mexican Spanish," J.B. Rael; (5) "Some Aspects…

  6. Proposed Department of Defense Policy on Air Installations Compatible Use Zones

    DTIC Science & Technology

    1973-06-01

    County PH GARCIA (URO ORTEGA K L SALAZAR* «I A SANCHEZ )ov»l County JlH SROWN AO MONTOYA* /ID ROSTRO TORRES Mtfuol County «OLD... BERNAL 3 C MARTINEZ* . ASHLEY POND ENIO RAEL Ml Rt|1lflMlitflllW#f :ATA S SANOO* ERT VELARDE )FFICIO WEM ID KING , O ROYBAL April

  7. Representing the Self in Sculpture

    ERIC Educational Resources Information Center

    Nelken, Miranda

    2011-01-01

    Deborah Rael-Buckley creates stunning figurative self-portraits in clay that layer "personal, cultural, historical, and biological imagery" in a narrative style. Her work provides an exciting challenge in three-dimensional self-portraits for eighth graders. In this article, the author suggests some exercises to get students brainstorming visual…

  8. What Work of Literature Do You Recommend for Its Use of a Strong Oral Tradition?

    ERIC Educational Resources Information Center

    Adams, Cindy S.; Lujan, Alfredo Celedon; Schulze, Patricia

    2003-01-01

    Presents three teachers' recommendations for works of literature that use a strong oral tradition. Discusses each of the teacher selections: "Harry Potter and the Sorcerer's Stone (J.K. Rowling); "Cuentos: Tales from the Hispanic Southwest" (compiled by Juan B. Rael); and "The Way to Rainy Mountain" (N. Scott Momaday). (SG)

  9. Data Qualification Report: Calculated Porosity and Porosity-Derived Values for Lithostratigraphic Units for use on the Yucca Mountain Project

    SciTech Connect

    P. Sanchez

    2001-05-30

    The qualification is being completed in accordance with the Data Qualification Plan DQP-NBS-GS-000006, Rev. 00 (CRWMS M&O 2001). The purpose of this data qualification activity is to evaluate for qualification the unqualified developed input and porosity output included in Data Tracking Number (DTN) M09910POROCALC.000. The main output of the analyses documented in DTN M09910POROCALC.000 is the calculated total porosity and effective porosity for 40 Yucca Mountain Project boreholes. The porosity data are used as input to Analysis Model Report (AMR) 10040, ''Rock Properties Model'' (MDL-NBS-GS-000004, Rev. 00), Interim Change Notice [ICN] 02 (CRWMS M&O 2000b). The output from the rock properties model is used as input to numerical physical-process modeling within the context of a relationship developed in the AMR between hydraulic conductivity, bound water and zeolitic zones for use in the unsaturated zone model. In accordance with procedure AP-3.15Q, the porosity output is not used in the direct calculation of Principal Factors for post-closure safety or disruptive events. The original source for DTN M09910POROCALC.000 is a Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M&O) report, ''Combined Porosity from Geophysical Logs'' (CRWMS M&O 1999a and hereafter referred to as Rael 1999). That report recalculated porosity results for both the historical boreholes covered in Nelson (1996), and the modern boreholes reported in CRWMS M&O (1996a,b). The porosity computations in Rael (1999) are based on density-porosity mathematical relationships requiring various input parameters, including bulk density, matrix density and air and/or fluid density and volumetric water content. The main output is computed total porosity and effective porosity reported on a foot-by-foot basis for each borehole, although volumetric water content is derived from neutron data as an interim output. This qualification report uses technical assessment and

  10. 77 FR 25538 - Quarterly Publication of Individuals, Who Have Chosen To Expatriate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ... KEILBAR PETER TIMOTHY KELLER PATRICIA DORIS KELLY ALEXANDER ANTHONY KELLY VIRGINIA RAE KEMPE TOBY NICHOLAS... NADIA STUBER ANDREAS PAUL STUBER KATRIN STUBER LISA RAE STUMP BEATRICE SUTER MARTIN KASPAR SYZ...

  11. TRITIUM-β-DECAY Experiments - the Direct way to the Absolute Neutrino Mass

    NASA Astrophysics Data System (ADS)

    Bornschein, Lutz

    2013-11-01

    Tritium-β-decay experiments provide the most sensitive approach to measure the absolute neutrino mass in a model independent way. The Karlsruhe Tritium Neutrino experiment KATRIN will measure the neutrino mass scale with an expected sensitivity of 0.2 eV/c2 (90% C.L.) and so will help to clarify the roles of neutrinos in the early universe. KATRIN investigates spectroscopically the electron spectrum from tritium β-decay 3 H -> 3 {He} + {e}^ - + bar ν e close to the kinematic endpoint of 18.6 keV. It will use a windowless gaseous tritium source in combination with an electrostatic filter for energy analysis. KATRIN is currently under construction at the Karlsruhe Institute of Technology (KIT) Campus North. This proceeding will give an overview of the status of the main components of the KATRIN experiment.

  12. Can one measure the Cosmic Neutrino Background?

    NASA Astrophysics Data System (ADS)

    Faessler, Amand; Hodák, Rastislav; Kovalenko, Sergey; Šimkovic, Fedor

    The Cosmic Microwave Background (CMB) yields information about our Universe at around 380,000 years after the Big Bang (BB). Due to the weak interaction of the neutrinos with matter, the Cosmic Neutrino Background (CNB) should give information about a much earlier time of our Universe, around one second after the BB. Probably, the most promising method to “see” the CNB is the capture of the electron neutrinos from the Background by Tritium, which then decays into 3He and an electron with the energy of the the Q-value = 18.562keV plus the electron neutrino rest mass. The “KArlsruhe TRItium Neutrino” (KATRIN) experiment, which is in preparation, seems presently the most sensitive proposed method for measuring the electron antineutrino mass. At the same time, KATRIN can also look by the reaction νe(˜ 1.95K) +3H →3He + e‑(Q = 18.6keV + m νec2). The capture of the Cosmic Background Neutrinos (CNB) should show in the electron spectrum as a peak by the electron neutrino rest mass above Q. Here, the possibility to see the CNB with KATRIN is studied. A detection of the CNB by KATRIN seems not to be possible at the moment. But KATRIN should be able to determine an upper limit for the local electron neutrino density of the CNB.

  13. Kamstrupp's Wow-Effect: Re-Examined and Expanded

    ERIC Educational Resources Information Center

    King, Elizabeth M.; Dickmann, Ellyn M.; Johnson, Barbara Z.

    2016-01-01

    This review examines Anne Katrine Kamstrupp's article "The wow-effect in science teacher education; technology; sociomateriality." In the discussion below we explore three key areas of her ethnographic research. First, we reconsider Kamstrupp's article through the lens of technology as a pedagogical choice and philosophy. This is…

  14. Environmental contaminants in oil field produced waters discharged into wetlands

    SciTech Connect

    Ramirez, P. Jr.

    1994-12-31

    The 866-acre Loch Katrine wetland complex in Park County, Wyoming provides habitat for many species of aquatic birds. The complex is sustained primarily by oil field produced waters. This study was designed to determine if constituents in oil field produced waters discharged into Custer Lake and to Loch Katrine pose a risk to aquatic birds inhabiting the wetlands. Trace elements, hydrocarbons and radium-226 concentrations were analyzed in water, sediment and biota collected from the complex during 1992. Arsenic, boron, radium-226 and zinc were elevated in some matrices. The presence of radium-226 in aquatic vegetation suggests that this radionuclide is available to aquatic birds. Oil and grease concentrations in water from the produced water discharge exceeded the maximum 10 mg/l permitted by the WDEQ (1990). Total aliphatic and aromatic hydrocarbon concentrations in sediments were highest at the produced water discharge, 6.376 {mu}g/g, followed by Custer Lake, 1.104 {mu}g/g. The higher levels of hydrocarbons found at Custer Lake, compared to Loch Katrine, may be explained by Custer Lake`s closer proximity to the discharge. Benzo(a)pyrene was not detected in bile from gadwalls collected at Loch Katrine but was detected in bile from northern shovelers collected at Custer Lake. Benzo(a)pyrene concentrations in northern shoveler bile ranged from 500 to 960 ng/g (ppb) wet weight. The presence of benzo(a)pyrene in the shovelers indicates exposure to petroleum hydrocarbons.

  15. Academic Debate: Publications Which Promote Political Agendas Have no Place in Scientific and Medical Journals, and Academics Should Refrain from Publishing in Such Journals.

    PubMed

    Glick, Shimon; Clarfield, A Mark; Strous, Rael D; Horton, Richard

    2015-01-01

    This paper presents the full debate held on October 1, 2014, which focused on the following resolution: "Publications which promote political agendas have no place in scientific and medical journals, and academics should refrain from publishing in such journals." The debate moderator was Professor Shimon Glick. Taking the pro stance was Professor A. Mark Clarfield; the con stance was held by Professor Rael D. Strous. Following the first part of the debate, Dr Richard Horton, Editor-in-Chief of The Lancet, gave his thoughts on the topic. This was followed by the opportunity for rebuttal by Professors Clarfield and Strous. The debate was summarized and closed by Professor Glick. This paper provides a slightly edited text of the debate, for ease of reading.

  16. Academic Debate: Publications Which Promote Political Agendas Have no Place in Scientific and Medical Journals, and Academics Should Refrain from Publishing in Such Journals

    PubMed Central

    Glick, Shimon; Clarfield, A. Mark; Strous, Rael D.; Horton, Richard

    2015-01-01

    This paper presents the full debate held on October 1, 2014, which focused on the following resolution: “Publications which promote political agendas have no place in scientific and medical journals, and academics should refrain from publishing in such journals.” The debate moderator was Professor Shimon Glick. Taking the pro stance was Professor A. Mark Clarfield; the con stance was held by Professor Rael D. Strous. Following the first part of the debate, Dr Richard Horton, Editor-in-Chief of The Lancet, gave his thoughts on the topic. This was followed by the opportunity for rebuttal by Professors Clarfield and Strous. The debate was summarized and closed by Professor Glick. This paper provides a slightly edited text of the debate, for ease of reading. PMID:25717385

  17. Aminoglycoside Resistance and Susceptibility Testing Errors in Acinetobacter baumannii-calcoaceticus Complex

    DTIC Science & Technology

    2010-04-01

    Robinson,5 Katrin Mende,1,6 and Clinton K. Murray1,2* Infectious Disease Service, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Fort Sam...Laboratory Services, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Fort Sam Houston, Texas 78234-62005; and Infectious Disease Clinical...by the Vitek 2 automated * Corresponding author. Mailing address: Infectious Disease Ser- vice, San Antonio Military Medical Center, Brooke Army

  18. Polymers from plants to develop biodegradable plastics.

    PubMed

    Conrad, Udo

    2005-11-01

    Katrin Neumann et al. have recently shown that transgenic tobacco and potato plants can accumulate high levels of cyanophycin, a possible source for poly-aspartate. This work opens the way to the future production of biodegradable plastics using a plant-based production system. Several problems need to be overcome first, such as growth retardation as a result of cyanophycin accumulating in the cytosol, and a co-production system needs to be developed for economical reasons.

  19. Final scientific and technical report: New experiments to measure the neutrino mass scale

    SciTech Connect

    Monreal, Benjamin

    2016-11-19

    In this work, we made material progress towards future measurements of the mass of the neutrino. The neutrino is a fundamental particle, first observed in the 1950s and subjected to particularly intense study over the past 20 years. It is now known to have some, non-zero mass, but we are in an unusual situation of knowing the mass exists but not knowing what value it takes. The mass may be determined by precise measurements of certain radioactive decay distributions, particularly the beta decay of tritium. The KATRIN experiment is an international project which is nearing the beginning of a tritium measurement campaign using a large electrostatic spectrumeter. This research included participation in KATRIN, including construction and delivery of a key calibration subsystem, the ``Rear Section''. To obtain sensitivity beyond KATRIN's, new techniques are required; this work included R\\&D on a new technique we call CRES (Cyclotron Resonance Electron Spectroscopy) which has promise to enable even-more-sensitive tritium decay measurements. We successfully carried out CRES spectroscopy in a model system in 2014, making an important step towards the design of a next-generation tritium experiment with new neutrino mass measurement abilities.

  20. Reisen im freien Fall - Teil 2: Das Zwillingsparadoxon aus dem Blickwinkel der ART

    NASA Astrophysics Data System (ADS)

    Sonne, Bernd; Weiß, Reinhard

    2013-07-01

    Nachdem wir uns mit den Prinzipien der ART und einigen Beispielen vertraut gemacht haben, kommen wir nun zur Berechnung des Zwillingsparadoxons aus Sicht des reisenden Zwillings. Dabei spielt das Äquivalenzprinzip eine große Rolle. Deshalb wird die Bewegungssituation noch einmal erläutert, diesmal aus Sicht von Katrin. Sie befindet sich in ihrem System S'in Ruhe. In ihrem System läuft die Zeit t'ab. Nach dem Start fühlt Katrin jedoch eine Kraft, die sie als Gravitationskraft interpretieren kann. Sie merkt es daran, dass sie in den Sitz gedrückt wird. Nach einiger Zeit werden die Triebwerke abgeschaltet, und das Raumschiff fliegt mit konstanter Geschwindigkeit weiter, Phase 2. Anschließend wird der Schub der Triebwerke solange umgekehrt, bis das Raumschiff irgendwo mit der Geschwindigkeit null am Umkehrpunkt U landet, Phase 3 (Abb. 15.1). Die Erde, auf der sich Michael befindet, bewegt sich mit x'(t') aus Sicht von Katrin im freien Fall von ihr weg, s. das Experiment mit dem steigenden Fahrstuhl in Abschn. 13.2.1.

  1. Unique forbidden beta decays and neutrino mass

    SciTech Connect

    Dvornický, Rastislav; Šimkovic, Fedor

    2015-10-28

    The measurement of the electron energy spectrum in single β decays close to the endpoint provides a direct determination of the neutrino masses. The most sensitive experiments use β decays with low Q value, e.g. KATRIN (tritium) and MARE (rhenium). We present the theoretical spectral shape of electrons emitted in the first, second, and fourth unique forbidden β decays. Our findings show that the Kurie functions for these unique forbidden β transitions are linear in the limit of massless neutrinos like the Kurie function of the allowed β decay of tritium.

  2. TRIMS: Validating T2 Molecular Effects for Neutrino Mass Experiments

    NASA Astrophysics Data System (ADS)

    Lin, Ying-Ting; Bodine, Laura; Enomoto, Sanshiro; Kallander, Matthew; Machado, Eric; Parno, Diana; Robertson, Hamish; Trims Collaboration

    2017-01-01

    The upcoming KATRIN and Project 8 experiments will measure the model-independent effective neutrino mass through the kinematics near the endpoint of tritium beta-decay. A critical systematic, however, is the understanding of the molecular final-state distribution populated by tritium decay. In fact, the current theory incorporated in the KATRIN analysis framework predicts an observable that disagrees with an experimental result from the 1950s. The Tritium Recoil-Ion Mass Spectrometer (TRIMS) experiment will reexamine branching ratio of the molecular tritium (T2) beta decay to the bound state (3HeT+). TRIMS consists of a magnet-guided time-of-flight mass spectrometer with a detector located on each end. By measuring the kinetic energy and time-of-flight difference of the ions and beta particles reaching the detectors, we will be able to distinguish molecular ions from atomic ones and hence derive the ratio in question.We will give an update on simulation software, analysis tools, and the apparatus, including early commissioning results. U.S. Department of Energy Office of Science, Office of Nuclear Physics, Award Number DE-FG02-97ER41020.

  3. Direct neutrino mass measurements

    NASA Astrophysics Data System (ADS)

    Thümmler, T.

    2011-07-01

    The determination of the neutrino rest mass plays an important role at the intersections of cosmology, particle physics and astroparticle physics. This topic is currently being addressed by two complementary approaches in laboratory experiments. Neutrinoless double beta decay experiments probe whether neutrinos are Majorana particles and determine an effective neutrino mass value. Single beta decay experiments such as KATRIN and MARE investigate the spectral shape of β-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Owing to neutrino flavour mixing, the neutrino mass parameter appears as an average of all neutrino mass eigenstates contributing to the electron neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. Applying an ultra-luminous molecular windowless gaseous tritium source and an integrating high-resolution spectrometer of MAC-E filter type, it allows β-spectroscopy close to the T 2 end-point with unprecedented precision and will reach a sensitivity of 200 meV/ c 2 (90% C.L.) on the neutrino rest mass.

  4. Transcription of Epstein-Barr virus-encoded nuclear antigen 1 promoter Qp is repressed by transforming growth factor-beta via Smad4 binding element in human BL cells.

    PubMed

    Liang, C L; Tsai, C N; Chung, P J; Chen, J L; Sun, C M; Chen, R H; Hong, J H; Chang, Y S

    2000-11-10

    In Epstein-Barr virus (EBV)-infected BL cells, the oncogenic EBV-encoded nuclear antigen 1 (EBNA 1) gene is directed from the latent promoter Qp. Yeast one-hybrid screen analysis using the -50 to -37 sequence of Qp as the bait was carried out to identify transcriptional factors that may control Qp activity. Results showed that Smad4 binds the -50 to -37 sequence of Qp, indicating that this promoter is potentially regulated by TGF-beta. The association of Smad4 with Qp was further confirmed by supershift of EMSA complexes using Smad4-specific antibody. The transfection of a Qp reporter construct in two EBV(+) BL cell lines, Rael and WW2, showed that Qp activity is repressed in response to the TGF-beta treatment. This repression involves the interaction of a Smad3/Smad4 complex and the transcriptional repressor TGIF, as determined by cotransfection assay and coimmunoprecipitation analysis. Results suggest that TGF-beta may transcriptionally repress Qp through the Smad4-binding site in human BL cells.

  5. Kamstrupp's wow-effect: re-examined and expanded

    NASA Astrophysics Data System (ADS)

    King, Elizabeth M.; Dickmann, Ellyn M.; Johnson, Barbara Z.

    2016-12-01

    This review examines Anne Katrine Kamstrupp's article "The wow-effect in science teacher education; technology; sociomateriality." In the discussion below we explore three key areas of her ethnographic research. First, we reconsider Kamstrupp's article through the lens of technology as a pedagogical choice and philosophy. This is followed by our discussion of aspects of her study within the context of a basic understanding that entry-level pre-service teachers need to fully understand both the process of learning and scientific principles as these are important foundational factors in determining whether or not the wow-effect will occur as expected. Finally, our review team presents multiple areas in Kamstrupp's article as potential points for further elaboration.

  6. Changes to Irradiation Conditions of VVER-1000 Surveillance Specimens Resulting from Fuel Assemblies with Greater Fuel Height

    NASA Astrophysics Data System (ADS)

    Panferov, Pavel; Kochkin, Viacheslav; Erak, Dmitry; Makhotin, Denis; Reshetnikov, Alexandr; Timofeev, Andrey

    2016-02-01

    The goal of the work was to obtain experimental data on the influence of newtype fuel assemblies with higher fuel rods on the irradiation conditions of surveillance specimens installed on the baffe of VVER-1000. For this purpose, two surveillance sets with container assemblies of the same design irradiated in reactors with different fuel assemblies in the core were investigated. Measurements of neutron dosimeters from these sets and retrospective measurements of 54Mn activity accumulated in each irradiated specimen allow a detailed distribution of the fast neutron flux in the containers to be obtained. Neutron calculations have been done using 3D discrete ordinate code KATRIN. On the basis of the obtained results, a change of the lead factor due to newtype fuel assemblies was evaluated for all types of VVER-1000 container assemblies.

  7. Prospects for cosmic neutrino detection in tritium experiments in the case of hierarchical neutrino masses

    SciTech Connect

    Blennow, Mattias

    2008-06-01

    We discuss the effects of neutrino mixing and the neutrino mass hierarchy when considering the capture of the cosmic neutrino background (CNB) on radioactive nuclei. The implications of mixing and hierarchy at future generations of tritium decay experiments are considered. We find that the CNB should be detectable at these experiments provided that the resolution for the kinetic energy of the outgoing electron can be pushed to a few 0.01 eV for the scenario with inverted neutrino mass hierarchy, about an order of magnitude better than that of the upcoming KATRIN experiment. Another order of magnitude improvement is needed in the case of normal neutrino mass hierarchy. We also note that mixing effects generally make the prospects for CNB detection worse due to an increased maximum energy of the normal beta decay background.

  8. Forbidden unique beta-decays and neutrino mass

    NASA Astrophysics Data System (ADS)

    Dvornický, Rastislav; Šimkovic, Fedor

    2013-12-01

    The measurement of the electron spectrum in beta-decays provides a robust direct determination of the values of neutrino masses. The planned rhenium beta-decay experiment, called the "Microcalorimeter Arrays for a Rhenium Experiment" (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which is expected to collect data in a near future. In this contribution we discuss the spectrum of emitted electrons close to the end point in the case of the first unique forbidden beta-decay of 79Se, 107Pd and 187Re. It is found that the p3/2-wave emission dominates over the s1/2-wave. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed beta-decay of 3H.

  9. The Absolute Mass of Neutrino and the First Unique Forbidden β-DECAY of 187Re

    NASA Astrophysics Data System (ADS)

    Dvornický, Rastislav; Šimkovic, Fedor; Muto, Kazuo

    2011-10-01

    The planned rhenium β-decay experiment MARE might probe the absolute mass scale of neutrinos with the same sensitivity as the tritium β-decay experiment KATRIN, which will start data taking in 2011 and will proceed for five years. We present the energy distribution of emitted electrons for the first unique forbidden β-decay of 187Re. It is found that the p-wave emission of electron dominates over the s-wave. By assuming mixing of three neutrinos the Kurie function for the rhenium β-decay is derived. It is shown that the Kurie plot near the endpoint is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed βof 3H.

  10. Absolute mass of neutrinos and the first unique forbidden β decay of Re187

    NASA Astrophysics Data System (ADS)

    Dvornický, Rastislav; Muto, Kazuo; Šimkovic, Fedor; Faessler, Amand

    2011-04-01

    The planned rhenium β-decay experiment, called the “Microcalorimeter Arrays for a Rhenium Experiment” (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which will take commissioning data in 2011 and will proceed for 5 years. We present the energy distribution of emitted electrons for the first unique forbidden β decay of Re187. It is found that the p-wave emission of electron dominates over the s wave. By assuming mixing of three neutrinos, the Kurie function for the rhenium β decay is derived. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed β decay of H3.

  11. Supercomputing Sheds Light on the Dark Universe

    SciTech Connect

    Salman Habib

    2012-11-15

    At Argonne National Laboratory, scientists are using supercomputers to shed light on one of the great mysteries in science today, the Dark Universe. With Mira, a petascale supercomputer at the Argonne Leadership Computing Facility, a team led by physicists Salman Habib and Katrin Heitmann will run the largest, most complex simulation of the universe ever attempted. By contrasting the results from Mira with state-of-the-art telescope surveys, the scientists hope to gain new insights into the distribution of matter in the universe, advancing future investigations of dark energy and dark matter into a new realm. The team's research was named a finalist for the 2012 Gordon Bell Prize, an award recognizing outstanding achievement in high-performance computing.

  12. Absolute mass of neutrinos and the first unique forbidden {beta} decay of {sup 187}Re

    SciTech Connect

    Dvornicky, Rastislav; Simkovic, Fedor; Muto, Kazuo; Faessler, Amand

    2011-04-15

    The planned rhenium {beta}-decay experiment, called the ''Microcalorimeter Arrays for a Rhenium Experiment'' (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which will take commissioning data in 2011 and will proceed for 5 years. We present the energy distribution of emitted electrons for the first unique forbidden {beta} decay of {sup 187}Re. It is found that the p-wave emission of electron dominates over the s wave. By assuming mixing of three neutrinos, the Kurie function for the rhenium {beta} decay is derived. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed {beta} decay of {sup 3}H.

  13. Investigation of durability of optical coatings in highly purified tritium gas

    SciTech Connect

    Fischer, S.; Schoenung, K.; Bornschein, B.; Rolli, R.; Schaefer, V.; Sturm, M.

    2015-03-15

    Anti-reflection coated windows are part of Raman spectroscopy systems for tritium analytics in the KATRIN experiment and fusion-related applications. Damages of such windows were observed after three months of expo-sure to highly purified tritium gas in the LOOPINO facility. In this work, the origin of the damages was investigated, identified and eliminated. Coating samples manufactured by various physical vapor deposition methods have been tested for durability by exposure to pure tritium gas and subsequent visual inspection. Electron beam deposited coatings showed indications for damage after 17 days of tritium exposure in contrast to samples manufactured by ion assisted deposition or sputtering. An improved coating layout of the sample cell is presented for reliable long-term monitoring of tritium gas using Raman spectroscopy. (authors)

  14. Post service examination of turbomolecular pumps after stress testing with Kg-scale tritium throughput

    SciTech Connect

    Priester, F.; Roelling, M.

    2015-03-15

    Turbomolecular pumps (TMP) will be used with large amounts of tritium in future fusion machines like ITER, DEMO and in the KATRIN Experiment. In this work, a stress test of a large, magnetically levitated TMP (Leybold MAG W2800) with a tritium throughput of 1.1 kg over 384 days of operation was performed at TLK. After this, the pump was dismantled and the tritium uptake in several parts was deter-mined. Especially the non-metallic parts of the pump have absorbed large amounts of tritium and are most likely responsible for the observed pollution of the process gas. The total tritium uptake of the TMP was estimated with 0.1-1.1 TBq. No radiation-induced damages were found on the inner parts of the pump. The TMP showed no signs of functional limitations during the 384 days of operation. (authors)

  15. Overview of the Project 8 Experiment

    NASA Astrophysics Data System (ADS)

    Vandevender, Brent; Project 8 Collaboration

    2016-09-01

    We present an overview of the Project 8 experiment, a concept for the next-generation direct neutrino mass measurement after KATRIN, with a sensitivity goal to cover the range of neutrino masses allowed by the inverted mass hierarchy. Project 8 is a tritium endpoint experiment based on Cyclotron Radiation Emission Spectroscopy (CRES) of beta decay electrons from an atomic tritium source. We demonstrate how this combination can offer advantages in both statistical and systematic uncertainties compared to existing technologies. We then present our staged approach to develop the technology for the final experiment, including a discussion of the demanding specifications for an atomic tritium source. This work is supported by the DOE Office of Science Early Career Research Program, and the Laboratory Directed Research and Development Program at Pacific Northwest National Laboratory, a multiprogram national laboratory operated by Battelle for the U.S.

  16. SDAV Viz July Progress Update: LANL

    SciTech Connect

    Sewell, Christopher Meyer

    2012-07-30

    SDAV Viz July Progress Update: (1) VPIC (Vector Particle in Cell) Kinetic Plasma Simulation Code - (a) Implemented first version of an in-situ adapter based on Paraview CoProcessing Library, (b) Three pipelines: vtkDataSetMapper, vtkContourFilter, vtkPistonContour, (c) Next, resolve issue at boundaries of processor domains; add more advanced viz/analysis pipelines; (2) Halo finding/merger trees - (a) Summer student Wathsala W. from University of Utah is working on data-parallel halo finder algorithm using PISTON, (b) Timo Bremer (LLNL), Valerio Pascucci (Utah), George Zagaris (Kitware), and LANL people are interested in using merger trees for tracking the evolution of halos in cosmo simulations; discussed possible overlap with work by Salman Habib and Katrin Heitmann (Argonne) during their visit to LANL 7/11; (3) PISTON integration in ParaView - Now available from ParaView github.

  17. Human Herpesvirus 8 LANA Interacts with Proteins of the mSin3 Corepressor Complex and Negatively Regulates Epstein-Barr Virus Gene Expression in Dually Infected PEL Cells

    PubMed Central

    Krithivas, Anita; Young, David B.; Liao, Gangling; Greene, Deborah; Hayward, S. Diane

    2000-01-01

    The human herpesvirus 8 (HHV-8) latency-associated nuclear antigen (LANA) is expressed in all latently HHV-8 infected cells and in HHV-8-associated tumors, including primary effusion lymphoma (PEL). To better understand the contribution of LANA to tumorigenesis and to the PEL phenotype, we performed a yeast two-hybrid screen which identified the corepressor protein SAP30 as a LANA binding protein. SAP30 is a constituent of a large multicomponent complex that brings histone deacetylases to the promoter. Glutathione S-transferase affinity assays confirmed interaction between LANA and SAP30 and also demonstrated interactions between LANA and two other members of the corepressor complex, mSin3A and CIR. The corepressors bound to the amino-terminal 340-amino-acid domain of LANA. In transient expression assays, this same domain of LANA mediated repression when targeted to a 5×Gal4tk-CAT reporter as a GAL4-LANA fusion. PEL cells have the unusual feature that they are frequently dually infected with both HHV-8 and Epstein-Barr virus (EBV). We found that EBV EBNA-1 expression is downregulated in PEL cells at both the RNA and protein levels. In transient expression assays, LANA repressed activated expression from the EBV Qp and Cp latency promoters. Reduction of endogenous Qp activity could also be demonstrated in EBV-infected Rael cells transfected with a LANA expression plasmid. In contrast to the effect of LANA on EBV latency promoters, LANA activated expression from its own promoter. The data indicate that LANA can mediate transcriptional repression through recruitment of an mSin3 corepressor complex and further that LANA-mediated repression is likely to contribute to the low level of EBV latency gene expression seen in dually infected PEL cells. PMID:11000236

  18. Is lead in tap water still a public health problem? An observational study in Glasgow.

    PubMed Central

    Watt, G. C.; Britton, A.; Gilmour, W. H.; Moore, M. R.; Murray, G. D.; Robertson, S. J.; Womersley, J.

    1996-01-01

    OBJECTIVE: To assess the relation between tap water lead and maternal blood lead concentrations and assess the exposure of infants to lead in tap water in a water supply area subjected to maximal water treatment to reduce plumbosolvency. DESIGN: Postal questionnaire survey and collection of kettle water from a representative sample of mothers; blood and further water samples were collected in a random sample of households and households with raised water lead concentrations. SETTING: Loch Katrine water supply area, Glasgow. SUBJECTS: 1812 mothers with a live infant born between October 1991 and September 1992. Blood lead concentrations were measured in 342 mothers. MAIN OUTCOME MEASURES: Mean geometric blood lead concentrations and the prevalence of raised tap water lead concentration. RESULTS: 17% of households had water lead concentration of 10 micrograms/l (48.3 nmol/l) or more in 1993 compared with 49% of households in 1981. Tap water lead remained the main correlate or raised maternal blood lead concentrations and accounted for 62% and 76% of cases of maternal blood lead concentrations above 5 and 10 micrograms/dl (0.24 and 0.48 mumol/l) respectively. The geometric mean maternal blood lead concentration was 3.65 micrograms/dl (0.18 mumol/l) in a random sample of mothers and 3.16 micrograms/dl (0.15 mumol/l) in mothers whose tap water lead concentrations were consistently below 2 micrograms/l (9.7 nmol/l). No mother in the study had a blood lead concentration above 25 micrograms/dl (1.21 mumol/l). An estimated 13% of infants were exposed via bottle feeds to tap water lead concentrations exceeding the World Health Organisation's guideline of 10 micrograms/l (48.3 nmol/l). CONCLUSIONS: Tap water lead and maternal blood led concentrations in the Loch Katrine water supply area have fallen substantially since the early 1980s. Maternal blood lead concentrations are well within limits currently considered safe for human health. Tap water lead is still a public health

  19. Clinician-scientist trainee: a German perspective.

    PubMed

    Bossé, Dominick; Milger, Katrin; Morty, Rory E

    2011-12-01

    Clinician-scientists are particularly well positioned to bring basic science findings to the patient's bedside; the ultimate objective of basic research in the health sciences. Concerns have recently been raised about the decreasing workforce of clinician-scientists in both the United States of America and in Canada; however, little is known about clinician-scientists elsewhere around the globe. The purpose of this article is two-fold: 1) to feature clinician-scientist training in Germany; and 2) to provide a comparison with the Canadian system. In a question/answer interview, Rory E. Morty, director of a leading clinician-scientist training program in Germany, and Katrin Milger, a physician and graduate from that program, draw a picture of clinician-scientist training and career opportunities in Germany, outlining the place of clinician-scientists in the German medical system, the advantages and drawbacks of this training, and government initiatives to promote training and career development of clinician-scientists. The interview is followed by a discussion comparing the German and Canadian clinician-scientist development programs, focusing on barriers to trainee recruitment and career progress, and efforts to eliminate the barriers encountered along this very demanding but also very rewarding career path.

  20. Forbidden unique beta-decays and neutrino mass

    SciTech Connect

    Dvornický, Rastislav; Šimkovic, Fedor

    2013-12-30

    The measurement of the electron spectrum in beta-decays provides a robust direct determination of the values of neutrino masses. The planned rhenium beta-decay experiment, called the “Microcalorimeter Arrays for a Rhenium Experiment” (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which is expected to collect data in a near future. In this contribution we discuss the spectrum of emitted electrons close to the end point in the case of the first unique forbidden beta-decay of {sup 79}Se, {sup 107}Pd and {sup 187}Re. It is found that the p{sub 3/2}-wave emission dominates over the s{sub 1/2}-wave. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed beta-decay of {sup 3}H.

  1. Beyond low beta-decay Q values

    SciTech Connect

    Mustonen, M. T.; Suhonen, J.

    2010-11-24

    Beta decays with low Q values can be utilized in the quest to determine the neutrino mass scale. This is being realized in two experiments, KATRIN and MARE, using tritium and {sup 187}Re, respectively. The beta-decay of {sup 187}Re had the lowest known Q value until 2005, when the beta decay of {sup 115}In to the first excited state of {sup 115}Sn was discovered in Gran Sasso underground laboratory. Last year two independent ion trap measurements confirmed that this decay breaks the former record by an order of magnitude.Our theoretical study on this tiny decay channel complemented the experimental effort by the JYFLTRAP group in Finland and HADES underground laboratory in Belgium. A significant discrepancy between the experimental and theoretical results was found. This might be explained by various atomic contributions known to grow larger as the Q value decreases. However, the traditional recipes for taking these effects into account break down on this new ultra-low Q value regime, providing new challenges for theorists on the borderline between nuclear and atomic physics.

  2. Probing the Absolute Mass Scale of Neutrinos

    SciTech Connect

    Prof. Joseph A. Formaggio

    2011-10-12

    The experimental efforts of the Neutrino Physics Group at MIT center primarily around the exploration of neutrino mass and its significance within the context of nuclear physics, particle physics, and cosmology. The group has played a prominent role in the Sudbury Neutrino Observatory, a neutrino experiment dedicated to measure neutrino oscillations from 8B neutrinos created in the sun. The group is now focusing its efforts in the measurement of the neutrino mass directly via the use of tritium beta decay. The MIT group has primary responsibilities in the Karlsruhe Tritium Neutrino mass experiment, expected to begin data taking by 2013. Specifically, the MIT group is responsible for the design and development of the global Monte Carlo framework to be used by the KATRIN collaboration, as well as responsibilities directly associated with the construction of the focal plane detector. In addition, the MIT group is sponsoring a new research endeavor for neutrino mass measurements, known as Project 8, to push beyond the limitations of current neutrino mass experiments.

  3. Upper bound of 0.28 eV on neutrino masses from the largest photometric redshift survey.

    PubMed

    Thomas, Shaun A; Abdalla, Filipe B; Lahav, Ofer

    2010-07-16

    We present a new limit of ∑m(v) ≤ 0.28 (95% CL) on the sum of the neutrino masses assuming a flat ΛCDM cosmology. This relaxes slightly to ∑m(ν) ≤ 0.34 and ∑m(v) ≤ 0.47 when quasinonlinear scales are removed and w≠ -1, respectively. These are derived from a new photometric catalogue of over 700,000 luminous red galaxies (MegaZ DR7) with a volume of 3.3  (Gpc h(-1))(3) and redshift range 0.45 < z < 0.65. The data are combined with WMAP 5-year CMB, baryon acoustic oscillations, supernovae, and a Hubble Space Telescope prior on h. When combined with WMAP these data are as constraining as adding all supernovae and baryon oscillation data available. The upper limit is one of the tightest constraints on the neutrino from cosmology or particle physics. Further, if these bounds hold, they all predict that current-to-next generation neutrino experiments, such as KATRIN, are unlikely to obtain a detection.

  4. High-accuracy mass spectrometry for fundamental studies.

    PubMed

    Kluge, H-Jürgen

    2010-01-01

    Mass spectrometry for fundamental studies in metrology and atomic, nuclear and particle physics requires extreme sensitivity and efficiency as well as ultimate resolving power and accuracy. An overview will be given on the global status of high-accuracy mass spectrometry for fundamental physics and metrology. Three quite different examples of modern mass spectrometric experiments in physics are presented: (i) the retardation spectrometer KATRIN at the Forschungszentrum Karlsruhe, employing electrostatic filtering in combination with magnetic-adiabatic collimation-the biggest mass spectrometer for determining the smallest mass, i.e. the mass of the electron anti-neutrino, (ii) the Experimental Cooler-Storage Ring at GSI-a mass spectrometer of medium size, relative to other accelerators, for determining medium-heavy masses and (iii) the Penning trap facility, SHIPTRAP, at GSI-the smallest mass spectrometer for determining the heaviest masses, those of super-heavy elements. Finally, a short view into the future will address the GSI project HITRAP at GSI for fundamental studies with highly-charged ions.

  5. Neutrino mass from triton decay

    NASA Astrophysics Data System (ADS)

    Weinheimer, Christian

    2006-07-01

    Since the discovery of neutrino flavor oscillation in different fields and by many different experiments we believe that neutrinos have non-vanishing masses in contrast to their current description within the Standard Model of particle physics. However, the absolute values of the neutrino masses, which are as important for particle physics as they are for cosmology and astrophysics, cannot be determined by oscillation experiments alone. There are a few ways to determine the neutrino mass scale, but the only model-independent method is the investigation of the electron energy spectrum of a β decay near its endpoint with tritium being the ideal isotope for the classical spectrometer set-up. The tritium β decay experiments at Mainz and Troitsk have recently been finished. At Mainz all relevant systematic uncertainties have been investigated by dedicated experiments yielding an upper limit of m(ν)<2.3eV/c (90% C.L.). The new Karlsruhe Tritium Neutrino Experiment (KATRIN) will enhance the sensitivity on the neutrino mass by an ultra-precise measurement of the tritium β decay spectrum near the endpoint by another order of magnitude down to 0.2 eV/c2 by using a very strong windowless gaseous molecular tritium source and a huge ultra-high resolution electrostatic spectrometer of MAC-E-Filter type. The recent achievements in test experiments show, that this very challenging experiment is feasible.

  6. Assessment of molecular effects on neutrino mass measurements from tritium β decay

    NASA Astrophysics Data System (ADS)

    Bodine, L. I.; Parno, D. Â. S.; Robertson, R. Â. G. Â. H.

    2015-03-01

    The β decay of molecular tritium currently provides the highest sensitivity in laboratory-based neutrino mass measurements. The upcoming Karlsruhe Tritium Neutrino (KATRIN) experiment will improve the sensitivity to 0.2 eV, making a percent-level quantitative understanding of molecular effects essential. The modern theoretical calculations available for neutrino mass experiments agree with spectroscopic data. Moreover, when neutrino mass experiments performed in the 1980s with gaseous tritium are reevaluated using these modern calculations, the extracted neutrino mass squared values are consistent with zero instead of being significantly negative. However, the calculated molecular final-state branching ratios are in conflict with dissociation experiments performed in the 1950s. We reexamine the theory of the final-state spectrum of molecular-tritium decay and its effect on the determination of the neutrino mass, with an emphasis on the role of the vibrational- and rotational-state distribution in the ground electronic state. General features can be reproduced quantitatively from considerations of kinematics and zero-point motion. We summarize the status of validation efforts and suggest means for resolving the apparent discrepancy in dissociation rates.

  7. Dead layer on silicon p-i-n diode charged-particle detectors

    SciTech Connect

    Wall, B. L.; Amsbaugh, John F.; Beglarian, A.; Bergmann, T.; Bichsel, H. C.; Bodine, L. I.; Boyd, N. M.; Burritt, Tom H.; Chaoui, Z.; Corona, T. J.; Doe, Peter J.; Enomoto, S.; Harms, F.; Harper, Gregory; Howe, M. A.; Martin, E. L.; Parno, D. S.; Peterson, David; Petzold, Linda; Renschler, R.; Robertson, R. G. H.; Schwarz, J.; Steidl, M.; Van Wechel, T. D.; VanDevender, Brent A.; Wustling, S.; Wierman, K. J.; Wilkerson, J. F.

    2014-04-21

    Abstract Semiconductor detectors in general have a dead layer at their surfaces that is either a result of natural or induced passivation, or is formed during the process of making a contact. Charged particles passing through this region produce ionization that is incompletely collected and recorded, which leads to departures from the ideal in both energy deposition and resolution. The silicon p-i-n diode used in the KATRIN neutrinomass experiment has such a dead layer. We have constructed a detailed Monte Carlo model for the passage of electrons from vacuum into a silicon detector, and compared the measured energy spectra to the predicted ones for a range of energies from 12 to 20 keV. The comparison provides experimental evidence that a substantial fraction of the ionization produced in the "dead" layer evidently escapes by discussion, with 46% being collected in the depletion zone and the balance being neutralized at the contact or by bulk recombination. The most elementary model of a thinner dead layer from which no charge is collected is strongly disfavored.

  8. Measurement of Turbulent Water Vapor Fluxes from Lightweight Unmanned Aircraft Systems

    NASA Astrophysics Data System (ADS)

    Thomas, R. M.; Ramanathan, V.; Nguyen, H.; Lehmann*, K.

    2010-12-01

    wind tunnel investigations and the outcomes from test flights planned for September 2010 at a marine location are discussed. Acknowledgments We would like to acknowledge the significant contributions to this system made by the late Katrin Lehmann whose life was tragically cut short by a hiking accident. Katrin was responsible for the initial design, construction and programming of the UAS elements, and in doing so laid solid foundations for the system. We are indebted to NOAA, for funding this project through the research grant NOAA NA17RJ1231. Thank you also to Mike Marston of NASA, the BAE systems crew Phillip Corcoran and Rafael Gaytan, and Mike Rizen of UCSD Physics workshop for their mission roles. We would also like to thank NSF for long term support of the C4 UAS Program.

  9. PREFACE: Beyond Kyoto - the necessary road

    NASA Astrophysics Data System (ADS)

    Margrethe Basse, Ellen

    2009-03-01

    Project Manager Henrik Dalgaard for his excellent editorial services and to stud.mag. Nanna Katrine Lüders Kaalund for her practical assistance with the proceedings. The European Commission under the Regional Development Fund has funded the conference and the publication of the proceedings.

  10. The effect of broadleaf woodland on aluminium speciation in stream water in an acid-sensitive area in the UK.

    PubMed

    Ryan, Jennifer L; Lynam, Philippa; Heal, Kate V; Palmer, Sheila M

    2012-11-15

    Acidification can result in the mobilisation and release of toxic inorganic monomeric aluminium (Al) species from soils into aquatic ecosystems. Although it is well-established that conifer trees enhance acidic atmospheric deposition and exacerbate soil and water acidification, the effect of broad-leaved woodland on soil and water acidification is less clear. This study investigated the effect of broadleaf woodland cover on the acid-base chemistry and Al species present in stream water, and processes controlling these in the acid-sensitive area around Loch Katrine, in the central Highlands, Scotland, UK, where broadleaf woodland expansion is occurring. A nested sampling approach was used to identify 22 stream sampling locations, in sub-catchments of 3.2-61 ha area and 0-45% broadleaf woodland cover. In addition, soils sampled from 68 locations were analysed to assess the influence of: (i) broadleaf woodland cover on soil characteristics and (ii) soil characteristics on stream water chemistry. Stream water pH was negatively correlated with sub-catchment % woodland cover, indicating that woodland cover is enhancing stream water acidification. Concentrations of all stream water Al species (monomeric total, organic and inorganic) were positively correlated with % woodland cover, although not significantly, but were below levels that are toxic to fish. Soil depth, O horizon depth and soil chemistry, particularly of the A horizon, appeared to be the dominant controls on stream water chemistry rather than woodland cover. There were significant differences in soil acid-base chemistry, with significantly lower O horizon pH and A horizon base saturation and higher A horizon exchangeable Al in the wooded catchments compared to the control. This is evidence that the mobile anion effect is already occurring in the study catchments and suggests that stream water acidification arising from broadleaf woodland expansion could occur, especially where tree density is high and acid

  11. Quantitative comparisons of numerical models of brittle deformation

    NASA Astrophysics Data System (ADS)

    Buiter, S.

    2009-04-01

    Numerical modelling of brittle deformation in the uppermost crust can be challenging owing to the requirement of an accurate pressure calculation, the ability to achieve post-yield deformation and localisation, and the choice of rheology (plasticity law). One way to approach these issues is to conduct model comparisons that can evaluate the effects of different implementations of brittle behaviour in crustal deformation models. We present a comparison of three brittle shortening experiments for fourteen different numerical codes, which use finite element, finite difference, boundary element and distinct element techniques. Our aim is to constrain and quantify the variability among models in order to improve our understanding of causes leading to differences between model results. Our first experiment of translation of a stable sand-like wedge serves as a reference that allows for testing against analytical solutions (e.g., taper angle, root-mean-square velocity and gravitational rate of work). The next two experiments investigate an unstable wedge in a sandbox-like setup which deforms by inward translation of a mobile wall. All models accommodate shortening by in-sequence formation of forward shear zones. We analyse the location, dip angle and spacing of thrusts in detail as previous comparisons have shown that these can be highly variable in numerical and analogue models of crustal shortening and extension. We find that an accurate implementation of boundary friction is important for our models. Our results are encouraging in the overall agreement in their dynamic evolution, but show at the same time the effort that is needed to understand shear zone evolution. GeoMod2008 Team: Markus Albertz, Michele Cooke, Susan Ellis, Taras Gerya, Luke Hodkinson, Kristin Hughes, Katrin Huhn, Boris Kaus, Walter Landry, Bertrand Maillot, Christophe Pascal, Anton Popov, Guido Schreurs, Christopher Beaumont, Tony Crook, Mario Del Castello and Yves Leroy

  12. Results from a 64-pixel PIN-diode detector system for low-energy beta-electrons

    NASA Astrophysics Data System (ADS)

    Wuestling, Sascha; Fraenkle, F.; Habermehl, F.; Renschler, P.; Steidl, M.

    2010-12-01

    The KATRIN neutrino mass experiment is based on a precise energy measurement (Δ E/ E=5×10 -5) of electrons emerging from tritium beta decay ( Emax=18.6 keV). This is done by a large electrostatic retarding spectrometer (MAC-E Filter), which is followed by an electron detector. Key requirements for this detector are a large sensitive area (˜80 cm 2), a certain energy resolution (Δ E=600 eV @ 18.6 keV) but also a certain spatial resolution (˜3 mm), which leads to a multi-pixel design. As a tentative design on the way to the final detector, but also for operational service on the so-called pre-spectrometer experiment, a detector system with a reduced size (16 cm 2) and a reduced pixel number (64), making use of a monolithic segmented silicon PIN diode, was designed and built. While the design and very first measurements have been presented in Wuestling et al. [6], this publication shows the operational performance of the detector system. The robust concept of the electronics allowed adaptation to mechanically different experimental setups. The spacial resolution of the detector system proved to be essential in examining Penning trap induced background and other effects in the pre-spectrometer experiment. The detector performance test runs include energy resolution and calibration, background rates, correlation between pixels (crosstalk), spatially resolved rate analysis, and a dead-layer measurement [7]. The detector allows for background searches with a sensitivity as low as 1.3×10 -3 cps/cm 2 in the energy range of 20 keV. This allows the pre-spectrometer to be characterized with e-gun illumination with a signal to background ratio of better than 10 5 and the search for ultra low Penning discharge emissions.

  13. Neutrino mass spectrum and future beta decay experiments

    NASA Astrophysics Data System (ADS)

    Farzan, Y.; Peres, O. L. G.; Smirnov, A. Yu.

    2001-09-01

    We study the discovery potential of future beta decay experiments on searches for the neutrino mass in the sub-eV range, and, in particular, KATRIN experiment with sensitivity m>0.3 eV. Effects of neutrino mass and mixing on the beta decay spectrum in the neutrino schemes which explain the solar and atmospheric neutrino data are discussed. The schemes which lead to observable effects contain one or two sets of quasi-degenerate states. Future beta decay measurements will allow to check the three-neutrino scheme with mass degeneracy, moreover, the possibility appears to measure the CP-violating Majorana phase. Effects in the four-neutrino schemes which can also explain the LSND data are strongly restricted by the results of Bugey and CHOOZ oscillation experiments: apart from bending of the spectrum and the shift of the end point one expects appearance of small kink of (<2%) size or suppressed tail after bending of the spectrum with rate below 2% of the expected rate for zero neutrino mass. We consider possible implications of future beta decay experiments for the neutrino mass spectrum, the determination of the absolute scale of neutrino mass and for establishing the nature of neutrinos. We show that beta decay measurements in combination with data from the oscillation and double beta decay experiments will allow to establish the structure of the scheme (hierarchical or non-hierarchical), the type of the hierarchy or ordering of states (normal or inverted) and to measure the relative CP-violating phase in the solar pair of states.

  14. "Effects of Stress on Decisions Under Uncertainty: A Meta-Analysis": Correction to Starcke and Brand (2016).

    PubMed

    2016-09-01

    Reports an error in "Effects of Stress on Decisions Under Uncertainty: A Meta-Analysis" by Katrin Starcke and Matthias Brand (Psychological Bulletin, Advanced Online Publication, May 23, 2016, np). It should have been reported that the inverted u-shaped relationship between cortisol stress responses and decision-making performance was only observed in female, but not in male participants as suggested by the study by van den Bos, Harteveld, and Stoop (2009). Corrected versions of the affected sentences are provided. (The following abstract of the original article appeared in record 2016-25465-001.) The purpose of the present meta-analysis was to quantify the effects that stress has on decisions made under uncertainty. We hypothesized that stress increases reward seeking and risk taking through alterations of dopamine firing rates and reduces executive control by hindering optimal prefrontal cortex functioning. In certain decision situations, increased reward seeking and risk taking is dysfunctional, whereas in others, this is not the case. We also assumed that the type of stressor plays a role. In addition, moderating variables are analyzed, such as the hormonal stress response, the time between stress onset and decisions, and the participants' age and gender. We included studies in the meta-analysis that investigated decision making after a laboratory stress-induction versus a control condition (k = 32 datasets, N = 1829 participants). A random-effects model revealed that overall, stress conditions lead to decisions that can be described as more disadvantageous, more reward seeking, and more risk taking than nonstress conditions (d = .17). In those situations in which increased reward seeking and risk taking is disadvantageous, stress had significant effects (d = .26), whereas in other situations, no effects were observed (d = .01). Effects were observed under processive stressors (d = .19), but not under systemic ones (d = .09). Moderation analyses did not reveal

  15. Austrian Carbon Calculator (ACC) - modelling soil carbon dynamics in Austrian soils

    NASA Astrophysics Data System (ADS)

    Sedy, Katrin; Freudenschuss, Alexandra; Zethner, Gehard; Spiegel, Heide; Franko, Uwe; Gründling, Ralf; Xaver Hölzl, Franz; Preinstorfer, Claudia; Haslmayr, Hans Peter; Formayer, Herbert

    2014-05-01

    Austrian Carbon Calculator (ACC) - modelling soil carbon dynamics in Austrian soils. The project funded by the Klima- und Energiefonds, Austrian Climate Research Programme, 4th call Authors: Katrin Sedy, Alexandra Freudenschuss, Gerhard Zethner (Environment Agency Austria), Heide Spiegel (Austrian Agency for Health and Food Safety), Uwe Franko, Ralf Gründling (Helmholtz Centre for Environmental Research) Climate change will affect plant productivity due to weather extremes. However, adverse effects could be diminished and satisfying production levels may be maintained with proper soil conditions. To sustain and optimize the potential of agricultural land for plant productivity it will be necessary to focus on preserving and increasing soil organic carbon (SOC). Carbon sequestration in agricultural soils is strongly influenced by management practice. The present management is affected by management practices that tend to speed up carbon loss. Crop rotation, soil cultivation and the management of crop residues are very important measures to influence carbon dynamics and soil fertility. For the future it will be crucial to focus on practical measures to optimize SOC and to improve soil structure. To predict SOC turnover the existing humus balance model the application of the "Carbon Candy Balance" was verified by results from Austrian long term field experiments and field data of selected farms. Thus the main aim of the project is to generate a carbon balancing tool box that can be applied in different agricultural production regions to assess humus dynamics due to agricultural management practices. The toolbox will allow the selection of specific regional input parameters for calculating the C-balance at field level. However farmers or other interested user can also apply their own field data to receive the result of C-dynamics under certain management practises within the next 100 years. At regional level the impact of predefined changes in agricultural management

  16. A new myeloarchitectonic map of the human neocortex based on data from the Vogt-Vogt school.

    PubMed

    Nieuwenhuys, Rudolf; Broere, Cees A J; Cerliani, Leonardo

    2015-09-01

    Katrin Amunts and their numerous associates, will yield a comprehensive 'supermap' of the structural organization of the human neocortex. For the time being, i. e., as long as this 'supermap' is not yet available, our map may provide a tentative frame of reference for (a) the morphological interpretation of the results of functional neuroimaging studies; (b) the selection of starting points (seed voxels, regions-of-interest) in diffusion tractography studies and

  17. Introducing litter quality to the ecosystem model LPJ-GUESS: Effects on short- and long-term soil carbon dynamics

    NASA Astrophysics Data System (ADS)

    Portner, Hanspeter; Wolf, Annett; Rühr, Nadine; Bugmann, Harald

    2010-05-01

    and 2007 [Rühr(2009)] and present soil carbon stocks [Heim et al.(2009)]. Our Results show, that for short-term soil carbon dynamics, e.g. estimates of heterotrophic soil respiration on an annual basis, the inclusion of the dependency on litter quality is not necessary, as the differences are minor only. However, when considering long-term soil carbon dynamics, e.g. simulated estimates of present soil carbon content, the dependency on litter quality shows effect, as there are correlations with specific site factors such as site location and forest type. The inclusion of the dependence on litter quality therefore may be of importance for the projection of future soil carbon dynamics, as forest types may well be altered due to climatic change. References [Heim et al.(2009)] A. Heim, L. Wehrli, W. Eugster, and M.W.I. Schmidt. Effects of sampling design on the probability to detect soil carbon stock changes at the swiss CarboEurope site Lägeren. Geoderma, 149(3-4):347-354, 2009. [Rühr(2009)] Nadine Katrin Rühr. Soil respiration in a mixed mountain forest : environmental drivers and partitioning of component fluxes. PhD thesis, ETH, 2009. [Smith et al.(2001)] Benjamin Smith, I. Colin Prentice, and Martin T. Sykes. Representation of vegetation dynamics in the modelling of terrestrial ecosystems: comparing two contrasting approaches within european climate space. Global Ecology and Biogeography, 10(6):621-637, 2001. [Tuomi et al.(2008)] Mikko Tuomi, Pekka Vanhala, Kristiina Karhu, Hannu Fritze, and Jari Liski. Heterotrophic soil respiration-Comparison of different models describing its temperature dependence. Ecological Modelling, 211(1-2): 182-190, 2008.

  18. Characterization of residuals from ice particles and droplets sampled in mid-latitude natural and aviation-influenced cirrus and in tropical deep convective cloud systems during ML-CIRRUS and ACRIDICON

    NASA Astrophysics Data System (ADS)

    Mertes, Stephan; Kästner, Udo; Schulz, Christiane; Klimach, Thomas; Krüger, Mira; Schneider, Johannes

    2015-04-01

    Airborne sampling of cloud particles inside different cirrus cloud types and inside deep convective clouds was conducted during the HALO missions ML-CIRRUS over Europe in March/April 2014 and ACRIDICON over Amazonia in September 2014. ML-CIRRUS aims at the investigation of the for-mation, evolution, microphysical state and radiative effects of different natural and aviation-induced cirrus clouds in the mid-latitudes. The main objectives of ACRIDICON are the microphysical vertical profiling, vertical aerosol transport and the cloud processing of aerosol particles (compari-son in- and outflow) of tropical deep convective cloud systems in clean and polluted air masses and over forested and deforested regions. The hydrometeors (drops and ice particles) are sampled by a counterflow virtual impactor (CVI) which has to be installed in the front part of the upper fuselage of the HALO aircraft. Such an intake position implies a size dependent abundance of cloud particles with respect to ambient conditions that was studied by particle trajectory simulations (Katrin Witte, HALO Technical Note 2008-003-A). On the other hand, this sampling location avoids that large ice crystals which could potentially bias the cloud particle sampling by shattering and break-up at the inlet shroud and tip enter the inlet. Both aspects as well as the flight conditions of HALO were taken into account for an optimized CVI design for HALO (HALO-CVI). Interstitial particles are pre-segregated and the condensed phase is evaporated/sublimated by the CVI, such that the residuals from cloud droplets and ice particles (CDR and IPR) can be microphysically and chemically analyzed by respective aerosol sensors located in the cabin. Although an even more comprehensive characterization of CDR and IPR was carried out, we like to report on the following measurements of certain aerosol properties. Particle number concentra-tion and size distribution are measured by a condensation particle counter (CPC) and an

  19. EDITORIAL: Focus on Plasma Medicine

    NASA Astrophysics Data System (ADS)

    Morfill, G. E.; Kong, M. G.; Zimmermann, J. L.

    2009-11-01

    -pressure microwave plasmas in an N2 and O2 gas mixture M K Singh, A Ogino and M Nagatsu Degradation of adhesion molecules of G361 melanoma cells by a non-thermal atmospheric pressure microplasma H J Lee, C H Shon, Y S Kim, S Kim, G C Kim and M G Kong The acidification of lipid film surfaces by non-thermal DBD at atmospheric pressure in air A Helmke, D Hoffmeister, N Mertens, S Emmert, J Schuette and W Vioel Reduction and degradation of amyloid aggregates by a pulsed radio-frequency cold atmospheric plasma jet D L Bayliss, J L Walsh, G Shama, F Iza and M G Kong The effect of low-temperature plasma on bacteria as observed by repeated AFM imaging René Pompl, Ferdinand Jamitzky, Tetsuji Shimizu, Bernd Steffes, Wolfram Bunk, Hans-Ulrich Schmidt, Matthias Georgi, Katrin Ramrath, Wilhelm Stolz, Robert W Stark, Takuya Urayama, Shuitsu Fujii and Gregor Eugen Morfill Removal and sterilization of biofilms and planktonic bacteria by microwave-induced argon plasma at atmospheric pressure Mi Hee Lee, Bong Joo Park, Soo Chang Jin, Dohyun Kim, Inho Han, Jungsung Kim, Soon O Hyun, Kie-Hyung Chung and Jong-Chul Park Cell permeabilization using a non-thermal plasma M Leduc, D Guay, R L Leask and S Coulombe Physical and biological mechanisms of direct plasma interaction with living tissue Danil Dobrynin, Gregory Fridman, Gary Friedman and Alexander Fridman Nosocomial infections-a new approach towards preventive medicine using plasmas G E Morfill, T Shimizu, B Steffes and H-U Schmidt Generation and transport mechanisms of chemical species by a post-discharge flow for inactivation of bacteria Takehiko Sato, Shiroh Ochiai and Takuya Urayama Low pressure plasma discharges for the sterilization and decontamination of surfaces F Rossi, O Kylián, H Rauscher, M Hasiwa and D Gilliland Contribution of a portable air plasma torch to rapid blood coagulation as a method of preventing bleeding S P Kuo, O Tarasenko, J Chang, S Popovic, C Y Chen, H W Fan, A Scott, M Lahiani, P Alusta, J D Drake and M Nikolic A two

  20. PREFACE: Preface

    NASA Astrophysics Data System (ADS)

    Angelova, Maia; Zakrzewski, Wojciech

    2011-03-01

    the meeting was that all plenary talks presented the state-of-the-art and were at the same time educational and exciting, promoting the multidisciplinary aspects of the research, and thus were inspirational for young scientists considering work in these fields. The plenary talks, each lasting 1 hour, were given by distinguished world experts and some young 'rising stars': Richard Ward, Ulf Leonhardt, Jens Eisert, Michael Berry, Shahn Majid, Arndt von Haeseler, Michio Jimbo, Katrin Wendland, Raymond Goldstein, Mark Trodden, Maria Vozmediano and Giulio Chiribella. The public lecture was given by Francesco Iachello and was open to participants and other people from the Newcastle-Durham region. In addition, talks of 30 minutes duration each and including more technical content, were given in four parallel sessions. Each parallel session had a designated time for informal interaction with the speakers, discussions of new directions of research and for forming new collaborations. The poster session, in a room where posters were exhibited for the duration of the conference, was easily accessible, and had a friendly and relaxed atmosphere, encouraging discussions of work and exchanges of new ideas. To secure a high quality scientific programme, all contributions were reviewed. Another interesting feature of the conference was the Open Forum on the Friday afternoon, which was lively and well attended. It took the form of a question and answer session with a panel chaired by Allan Solomon, with the following members: Gerald Goldin, Jean-Pierre Gazeau, Mark Trodden and Giulio Chiribella. The focus was on new directions of research, novel applications and the further development of group theory, education, training and career opportunities for young researchers. The participants were asked to submit questions in advance; examples are: "What is the role of symmetries and conservation principles in deducing underlying physics from experimental data?" and "What are the most

  1. PREFACE: The IARU International Scientific Congress on Climate Change: Global Risks, Challenges and Decisions (10-12 March, Copenhagen, Denmark)

    NASA Astrophysics Data System (ADS)

    2009-01-01

    revitalization of ecosystem services Key Message 6: Meeting the Challenge To achieve the societal transformation required to meet the climate change challenge, we must overcome a number of significant constraints and seize critical opportunities These include reducing inertia in social and economic systems; building on a growing public desire for governments to act on climate change; removing implicit and explicit subsidies; reducing the influence of vested interests that increase emissions and reduce resilience; enabling the shifts from ineffective governance and weak institutions to innovative leadership in government, the private sector and civil society; and engaging society in the transition to norms and practices that foster sustainability The editors of the volume are all the session chairs: Professor Agus Sari Dr Aled Jones Science Manager Anders Viksø-Nielsen Dr Andreas Barkman Professor Anette Reenberg Professor Ann Henderson-Sellers Professor Anthony J McMichael Dr Anthony Patt Dr Bette Otto-Bliesner Dr Cameron Hepburn Dr Carlos Nobre Dr Carol Turley Dr Chris Hope Professor Chris Turney Professor Claus Felby Professor Coleen Vogel Professor Dale Jamieson Professor Daniel M Kammen Senior Scientist Detlef F Sprinz Professor Diana Ürge-Vorsatz Professor Dorthe Dahl-Jensen PhD Fatima Denton Director Generel Frances Seymour Dr Frank Jotzo Professor Harold Mooney Director Henrik Bindslev Mr Jamie Pittock Professor Jacquie Burgess Dr James E Hansen Professor Jiahua Pan Dr Jill Jäger Professor Jim Skea Professor Johan Rockström Dr John Christensen Professor John Mitchell Professor John R Porter Professor Joyeeta Gupta Professor Jørgen E Olesen Professor Karen O'Brien Dr Kazuhiko Takeuchi Dr Katrine Krogh Andersen Professor Keith Paustian Professor Ken Caldeira Professor Kevin Anderson Dr Koko Warner Professor Konrad Steffen Professor Liping Zhou Professor Louise Fresco Professor Maria Carmen Lemos Professor Mark Ashton Dr Mark Stafford-Smith Dr Martin Claussen Dr Martin

  2. EDITORIAL: Focus on Iron-Based Superconductors FOCUS ON IRON-BASED SUPERCONDUCTORS

    NASA Astrophysics Data System (ADS)

    Hosono, Hideo; Ren, Zhi-An

    2009-02-01

    Elastic theory for the vortex-lattice melting in iron-based high-Tc superconductors Q-H Chen, Q-M Nie, J-P Lv and T-C Au Yeung Electronic properties of LaO1-xFxFeAs in the normal state probed by NMR/NQR H-J Grafe, G Lang, F Hammerath, D Paar, K Manthey, K Koch, H Rosner, N J Curro, G Behr, J Werner, N Leps, R Klingeler, H-H Klauss, F J Litterst and B Büchner AFe2As2 (A = Ca, Sr, Ba, Eu) and SrFe2-xTMxAs2 (TM = Mn, Co, Ni): crystal structure, charge doping, magnetism and superconductivity Deepa Kasinathan, Alim Ormeci, Katrin Koch, Ulrich Burkhardt, Walter Schnelle, Andreas Leithe-Jasper and Helge Rosner Impurity states in a family of antiferromagnetic iron arsenides Qiang Han and Z D Wang Coherence-incoherence crossover in the normal state of iron oxypnictides and importance of Hund's rule coupling K Haule and G Kotliar Electronic structure of heavily electron-doped BaFe1.7Co0.3As2 studied by angle-resolved photoemission Y Sekiba, T Sato, K Nakayama, K Terashima, P Richard, J H Bowen, H Ding, Y-M Xu, L J Li, G H Cao, Z-A Xu and T Takahashi Absorption and photoemission spectroscopy of rare-earth oxypnictides T Kroll, F Roth, A Koitzsch, R Kraus, D R Batchelor, J Werner, G Behr, B Büchner and M Knupfer Superconductivity in LnFePO (Ln = La, Pr and Nd) single crystals R E Baumbach, J J Hamlin, L Shu, D A Zocco, N M Crisosto and M B Maple Unconventional pairing originating from disconnected Fermi surfaces in the iron-based superconductor Kazuhiko Kuroki, Seiichiro Onari, Ryotaro Arita, Hidetomo Usui, Yukio Tanaka, Hiroshi Kontani and Hideo Aoki Near-degeneracy of several pairing channels in multiorbital models for the Fe pnictides S Graser, T A Maier, P J Hirschfeld and D J Scalapino Investigation of superconducting gap structure in TbFeAsO0.9F0.1 using point contact Andreev reflection K A Yates, K Morrison, J A Rodgers, G B S Penny, J-W G Bos, J P Attfield and L F Cohen Competition of magnetism and superconductivity in underdoped (Ba1-xKx)Fe2As2 Marianne Rotter, Marcus