133 research outputs found

    Fault current tests of a 5-m HTS cable

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    Unravelling Mycosphaerella: do you believe in genera?

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    Many fungal genera have been defined based on single characters considered to be informative at the generic level. In addition, many unrelated taxa have been aggregated in genera because they shared apparently similar morphological characters arising from adaptation to similar niches and convergent evolution. This problem is aptly illustrated in Mycosphaerella. In its broadest definition, this genus of mainly leaf infecting fungi incorporates more than 30 form genera that share similar phenotypic characters mostly associated with structures produced on plant tissue or in culture. DNA sequence data derived from the LSU gene in the present study distinguish several clades and families in what has hitherto been considered to represent the Mycosphaerellaceae. In some cases, these clades represent recognisable monophyletic lineages linked to well circumscribed anamorphs. This association is complicated, however, by the fact that morphologically similar form genera are scattered throughout the order (Capnodiales), and for some species more than one morph is expressed depending on cultural conditions and media employed for cultivation. The present study shows that Mycosphaerella s.s. should best be limited to taxa with Ramularia anamorphs, with other well defined clades in the Mycosphaerellaceae representing Cercospora, Cercosporella, Dothistroma, Lecanosticta, Phaeophleospora, Polythrincium, Pseudocercospora, Ramulispora, Septoria and Sonderhenia. The genus Teratosphaeria accommodates taxa with Kirramyces anamorphs, while other clades supported in the Teratosphaeriaceae include Baudoinea, Capnobotryella, Devriesia, Penidiella, Phaeothecoidea, Readeriella, Staninwardia and Stenella. The genus Schizothyrium with Zygophiala anamorphs is supported as belonging to the Schizothyriaceae, while Dissoconium and Ramichloridium appear to represent a distinct family. Several clades remain unresolved due to limited sampling. Mycosphaerella, which has hitherto been used as a term of convenience to describe ascomycetes with solitary ascomata, bitunicate asci and 1-septate ascospores, represents numerous genera and several families yet to be defined in future studies

    Recent results from a folded waveguide ICRF Antenna development project

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    Preliminary high power tests have been performed on a folded waveguide (FWG) ICRF launcher with a curved coupling faceplate installed. Two alternative faceplate configurations have been built and tested at low power and will be tested at high power in the near future. The new designs include a dipole plate which provides a 0-<font face="symbol">p</font> launch spectrum and a more transparent, flexible monopole face plate configuration. This FWG design is a 12 vane, 57 MHz design with a 0.31 m square cross section. The FWG can be installed with either fast wave or ion-Bernstein wave polarization and can also be retracted behind a vacuum isolation valve. A 1 x 4 FWG array optimized for fast wave current drive on DIII-D has been conceptualized

    Exotic ρ±ρ0\rho^\pm\rho^0 state photoproduction

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    It is shown that the list of unusual mesons planned for a careful study in photoproduction can be extended by the exotic states X±(1600)X^\pm(1600) with IG(JPC)=2+(2++)I^G(J ^{PC})=2^+(2^{++}) which should be looked for in the ρ±ρ0\rho^\pm\rho^0 decay channels in the reactions γNρ±ρ0N\gamma N\to\rho^\pm\rho^0N and γNρ±ρ0Δ\gamma N\to\rho^\pm \rho^0\Delta. The full classification of the ρ±ρ0\rho^\pm\rho^0 states by their quantum numbers is presented. A simple model for the spin structure of the γpf2(1270)p \gamma p\to f_2(1270)p, γpa20(1320)p\gamma p\to a^0_2(1320)p, and γNX±(N,Δ)\gamma N\to X^\pm (N, \Delta) reaction amplitudes is formulated and the tentative estimates of the corresponding cross sections at the incident photon energy Eγ6E_\gamma\approx 6 GeV are obtained: σ(γpf2(1270)p)0.12\sigma(\gamma p\to f_2(1270)p)\approx0.12 μ\mub, σ(γpa20(1320)p)0.25 \sigma(\gamma p\to a^0_2(1320)p)\approx0.25 μ\mub, σ(γNX±Nρ±ρ0N)0.018\sigma(\gamma N\to X^\pm N\to\rho^\pm\rho^0N)\approx0.018 μ\mub, and σ(γpXΔ++ρρ0Δ++)0.031\sigma(\gamma p\to X^-\Delta^{++ }\to\rho^-\rho^0\Delta^{++})\approx0.031 μ\mub. The problem of the X±X^\pm signal extraction from the natural background due to the other π±π0π+π\pi^\pm\pi^0 \pi^+\pi^- production channels is discussed. In particular the estimates are presented for the γph1(1170)π+n\gamma p\to h_1(1170)\pi^+n, γpρ+nπ+π0π+πn\gamma p\to\rho'^{+}n\to \pi^+\pi^0\pi^+\pi^-n, and γpωρ0p\gamma p\to\omega\rho^0p reaction cross sections. Our main conclusion is that the search for the exotic X±(2+(2++))X^\pm(2^+(2^{++})) states is quite feasible at JEFLAB facility. The expected yield of the γNX±Nρ±ρ0N\gamma N\to X^\pm N\to\rho^\pm\rho^0N events in a 30-day run at the 100% detection efficiency approximates 2.8×1062.8\times10^6 events.Comment: 19 pages, revtex, 1 figure in postscipt, some comments and references added, a few minor typos corrected, to be published in Phys. Rev.

    The rapid atmospheric monitoring system of the Pierre Auger Observatory

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    The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10(17) eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e. g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or 'rapid') monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction

    Depth Of Maximum Of Air-shower Profiles At The Pierre Auger Observatory. I. Measurements At Energies Above 1017.8ev

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    The Rapid Atmospheric Monitoring System of the Pierre Auger Observatory

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    The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10^17 eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e.g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or "rapid") monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction
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