WorldWideScience

Sample records for triggered whistler emissions

  1. Numerical simulation of whistler-triggered VLF emissions observed in Antartica

    Energy Technology Data Exchange (ETDEWEB)

    Nunn, D. [Southhampton Univ., Southhampton (United Kingdom); Smith, A.J. [British Antarctic Survey, Cambridge (United Kingdom)

    1996-03-01

    The authors have extracted from VLF databases from British Antarctica Survey data taken at Halley and Faraday stations, examples of whistler-triggered emissions (WTE). The WTE are relatively narrow band emissions triggered by natural background whistlers undergoing nonlinear wave particle interactions generally in the equatorial regions. They occur with either rising or falling frequency relative to the triggering waves. Using a Vlasov type code the authors are able to simulate the types of emissions which are observed. 24 refs., 8 figs., 3 tabs.

  2. Modulation Analysis of Whistler Mode Sidebands in VLF-Triggered Emissions and Implications for Conditions of Nonlinear Growth

    Science.gov (United States)

    Costabile, Jamie D.; Gołkowski, Mark; Wall, Randall E.

    2017-12-01

    Experimental observations of very low frequency (VLF) triggered emissions are an important resource in investigation of nonlinear wave-particle interactions between whistler mode waves and energetic electrons in the Earth's radiation belts. Magnetospherically generated whistler mode sidebands observed during the Siple Station wave injection experiment are analyzed using a mixed modulation model and the MINUIT minimization package. The observed sidebands are found to exhibit features of both amplitude and frequency modulation of the input carrier wave with frequency modulation becoming more prominent as the observed amplitudes of the carrier and sidebands increase. A nonlinear whistler mode wave growth formulation based on phase bunching of counterstreaming electrons within a well-defined phase trap is shown to reproduce the salient features of the sideband observations. Whistler mode sideband amplitude is shown to be affected by the shape and uniformity of the trap.

  3. Whistler Triggered Upper Band Chorus Observed in Alaska

    Science.gov (United States)

    Hosseini, P.; Golkowski, M.

    2017-12-01

    VLF radiation from lightning discharges is one of several sources of energy injection into the inner magnetosphere from the Earth. Lightning discharges initially produce a broadband impulse or `sferic' but after propagation in the dispersive magnetosphere this waveform soon becomes quasi narrow band with the characteristic spectrographic form of the whistler. Most of the lightning induced VLF wave energy injected into the magnetosphere will be unducted with a k-vector which becomes increasingly oblique. Although unducted radiation is ubiquitous throughout the inner magnetosphere, it is generally of a low amplitude due to Landau damping and is not expected to produce strong nonlinear phenomena such as triggered emissions and chorus waves. However, VLF wave energy ducted or trapped in field-aligned plasma density enhancements can have relatively large amplitudes due to focusing and also linear cyclotron resonance growth. Therefore high amplitude ducted whistler waves can trigger a number of complex nonlinear phenomena. These include the triggering of VLF emissions and triggering of VLF hiss or chorus. Such phenomena are generally considered to result from nonlinear electron cyclotron phase trapping. Observation of such VLF emissions triggered by natural whistlers have been reported since the 1970s in Antarctica. We present observations of whistlers triggered upper band chorus emission from Alaska. Dispersion analyze of whistlers determine the L-shell range to be 4.5 clear frequency band gap between upper and lower band of the observed chorus emissions. The observations point to ducted chorus generation in the vicinity of the plasmapause boundary.

  4. Whistlers and audio-frequency emissions monthly summaries of whistlers and emissions for the period July 1957 - December 1958

    CERN Document Server

    Morgan, M G

    1965-01-01

    Annals of the International Geophysical Year, Volume 37: Whistlers and Audio-Frequency Emissions presents the principal results obtained in Whistlers-East synoptic program publications. Although whistlers can be observed at any time of day, it is found that they occur primarily at night. The greatest incidence of whistlers during the International Geophysical Year (IGY) period occurred in both hemispheres in the geomagnetic latitude range 50-60ʻ. The day-to-day correlation of whistler activity at geomagnetically conjugate stations was sometimes very low and sometimes remarkably high. This book

  5. Bursty emission of whistler waves in association with plasmoid collision

    Directory of Open Access Journals (Sweden)

    K. Fujimoto

    2017-07-01

    Full Text Available A new mechanism to generate whistler waves in the course of collisionless magnetic reconnection is proposed. It is found that intense whistler emissions occur in association with plasmoid collisions. The key processes are strong perpendicular heating of the electrons through a secondary magnetic reconnection during plasmoid collision and the subsequent compression of the ambient magnetic field, leading to whistler instability due to the electron temperature anisotropy. The emissions have a bursty nature, completing in a short time within the ion timescales, as has often been observed in the Earth's magnetosphere. The whistler waves can accelerate the electrons in the parallel direction, contributing to the generation of high-energy electrons. The present study suggests that the bursty emission of whistler waves could be an indicator of plasmoid collisions and the associated particle energization during collisionless magnetic reconnection.

  6. New results of investigations of whistler-mode chorus emissions

    Directory of Open Access Journals (Sweden)

    O. Santolík

    2008-07-01

    Full Text Available This review summarizes selected recent results obtained during investigation of whistler-mode chorus emissions in the Earth's magnetosphere. Special attention is paid to results published during the last five years, with a focus on the results of the CLUSTER project. The nonlinear nature of chorus emissions is demonstrated using both theoretical results and measurements. Selected areas of research on whistler-mode chorus are covered and the paper especially reports new results on substructure and amplitudes of chorus wave packets, on new observations of frequency differences of chorus wave packets at different points in space and on their possible interpretations, on results concerning determination of position and size of the source region of chorus, on recent observational and theoretical results which lead to improved description of propagation of chorus from its source, and, finally, on comparison of chorus measurements with corresponding values deduced from nonlinear theory and simulations.

  7. New results of investigations of whistler-mode chorus emissions

    Czech Academy of Sciences Publication Activity Database

    Santolík, Ondřej

    2008-01-01

    Roč. 15, č. 4 (2008), s. 621-630 ISSN 1023-5809 R&D Projects: GA AV ČR IAA301120601 Grant - others: NASA (US) NNX07AI24G; ESA PECS(XE) 98025 Institutional research plan: CEZ:AV0Z30420517 Keywords : chorus emissions * whistler-mode * Earth's magnetosphere Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.022, year: 2008 http://www.nonlin-processes-geophys.net/15/621/2008/

  8. Influence of Whistler Turbulence on Fast Electron Distribution and Their Microwave Emissions in a Flare Loop

    Science.gov (United States)

    Filatov, L. V.; Melnikov, V. F.

    2017-12-01

    The influence of whistlers on the distribution and gyrosynchrotron radiation of fast electrons injected into a coronal magnetic trap is considered. The kinetic equation in the Fokker-Planck approximation with consideration of fast electron scattering, both on background plasma particles and on whistlers, is solved for an inhomogeneous trap. It is supposed that the source of whistlers is a nonstationary process of flare energy release. Having found the fast electron distribution, we can calculate their gyrosynchrotron microwave emission. The influence of nonthermal electron scattering on whistlers are compared with the effects of scattering on Coulomb collisions. It is shown that whistlers considerably modify the emission characteristics of a loop at a certain energy density; in particular, they steepen the frequency spectrum. This is useful for microwave diagnostics of plasma turbulence in the flare loop.

  9. Whistler mode electron cyclotron emission from energetic electrons in TMX-upgrade

    International Nuclear Information System (INIS)

    Lasnier, C.J.; Ellis, R.F.; Tsakiris, G.D.

    1988-01-01

    Measurements are presented of axially propagating whistler mode electron cyclotron emission (WECE) from the energetic electrons in the East end cell of TMX-Upgrade. The measurements were made in the frequency ranges 12.5-18 GHz and 29-40 GHz employing swept and fixed frequency super-heterodyne receivers and a spherical dish antenna. These measurements are compared with a one dimensional radiation transport model which treats whistler mode emission, absorption, and propagation for an electron population which has two components: a cold thermal component and an energetic relativistic, mirror trapped component. It is shown firstly that the measured emission is in good agreement with the predictions of the WECE model. Secondly, for low to moderate cold electron densities, and for detection frequencies slightly less than the minimum electron cyclotron frequency in the magnetic well, the emission achieves black body levels, yielding an effective hot electron temperature. At higher cold electron densities and/or higher frequencies cold plasma effects limit the diagnostic capabilities of whistler emission in so far as the hot electrons are concerned. (author)

  10. Relativistic electron acceleration by whistler-mode chorus emissions associated with substorms

    Science.gov (United States)

    Omura, Yoshiharu

    Whistler-mode chorus emissions are generated at the geomagnetic equator by injection of energetic electrons into the inner magnetosphere during geomagnetically disturbed periods of substorms[1]. We perform test particle simulations assuming whistler-mode chorus wave packets that are generated at the geomagnetic equator propagate away from the equator in both poleward directions. While electrons in the energy range 10 - 100 keV are primarily responsible for the generation of chorus waves through pitch angle diffusion into the loss cone, it has been found that a fraction of the higher-energy electrons from a few hundred keV to a few MeV are effectively accelerated by chorus due to special nonlinear trapping processes called relativistic turning acceleration (RTA)[2] and ultra-relativistic acceleration (URA)[3]. In the present study we confirm that the RTA and URA processes take place for a wave packet with variable frequency such as that occurring in a rising tone of chorus emissions. We study the efficiency of the RTA and URA processes for different particle energies. A Green's function method is used to describe the evolution of the particle energy distribution function. The RTA and URA processes due to chorus emissions create a high-energy tail in the electron energy distribution function[4]. The shape of the high-energy tail is determined by the distribution function of the seed electrons in the lower-energy range. The RTA and URA can accelerate electrons in a much shorter timescale than that estimated by quasi-linear diffusion theory, e.g., it typically takes tens of minutes to hours for a few keV seed electrons to be accelerated to energies of a few MeV by RTA and URA. References 1. Y. Omura, Y. Katoh, and D. Summers, Theory and simulation of the generation of whistlermode chorus, J. Geophys. Res., in press. 2. Y. Omura, N. Furuya, D. Summers, J Geophys. Res., Vol. 112, A06236, doi:10.1029/2006JA012243, 2007. 3. D. Summers and Y. Omura, Geophys. Res. Lett., 34

  11. Sources of two-dimensional supercritical perpendicular shock nonstationarity: nonlinear whistler emission versus shock front self-reformation

    Science.gov (United States)

    Lembege, B.; Savoini, P.; Hellinger, P.; Travnicek, P.

    2009-12-01

    Two-dimensional (2-D) full particle electromagnetic simulations are used for analysing in detail different nonstationary behaviors of perpendicular supercritical shocks (Lembège et al., 2009). A recent study (Hellinger et al., 2007) has previously evidenced that the shock front is dominated by the emission of coherent large amplitude whistler waves for some plasma conditions and shock regimes. These whistler waves are emitted in two-dimensional perpendicular shocks and inhibit the self-reformation driven by the accumulation of reflected ions: then, the shock front appears almost "quasistationary", a result which could seem in apparent contradiction with previous results. The present study allows to clarify the situation by bringing new complementary results:(i) there exists a transition regime around a critical Mach number threshold Mwwe, within which both self-reformation and whistler waves emission can co-exist. (ii) Below (above) this threshold regime, the self-reformation (whistler waves emission) is fully retrieved and becomes dominant. (iii) As MA is larger than Mwwe, this shock front looks "quasi-stationary" in 1-D y-averaged fields profiles, but in fact is nonstationary in full 2-D profiles. Moreover, this nonstationarity is characterized by a quasi-periodic reinforcement of nonlinear waves emission from the ramp. This effect results from the fact that the emission of nonlinear whistler waves varies in time according to the local need for balancing the nonlinear effects at the shock ramp (steepening). (iv) These results are observed for a strictly perpendicular shock, as B0 is within the simulation plane; in contrast, as B0 is perpendicular to the simulation plane, no whistler waves emission is evidenced even for large Mach number; only self-reformation is observed. The coexistence of both processes within the transition regime is characterized by a rapid occurrence of the self-reformation at early time of a run, while nonlinear waves are dominating the

  12. Systematic analysis of whistler-mode emissions below the lower hybrid frequency based on the data of the Cluster project.

    Science.gov (United States)

    Nemec, F.; Santolik, O.; Gereova, K.; Macusova, E.; Cornilleau-Wehrlin, N.

    2003-12-01

    We report results of a systematic analysis of equatorial noise below the local lower hybrid frequency. Our analysis is based on the entire data set collected by the STAFF-SA instruments on board the Cluster spacecraft during the first two years of operation (2001 - 2002). We compare intensities of equatorial noise with other whistler-mode emissions, for example with chorus or hiss. The results indicate that these emissions can play a significant role in the dynamics of the inner magnetosphere. Using the multipoint measurement we show considerable spatio-temporal variations of the wave intensity.

  13. Quasielectrostatic whistler wave radiation from the hot electron emission of a laser-produced plasma

    International Nuclear Information System (INIS)

    Vincena, Stephen; Gekelman, Walter; Maggs, James; Collette, Andrew; Van Zeeland, M. A.

    2008-01-01

    Measurements are presented of radiated wave electric fields which result from the creation of a dense, laser-produced plasma within a large, uniform background magnetoplasma. The radiated field patterns are consistent for waves propagating along the quasielectrostatic branch of the whistler wave dispersion curve calculated from the background plasma parameters. The energy source of these waves coincides with an observed energetic tail electron population escaping the laser-produced plasma. A prominent feature of the radiated electric fields is a bipolar spike in both time and space, with a cross-field size near that of the initial escaping electron burst and a duration equivalent to one oscillation at the lower hybrid frequency within the background plasma. Additionally, time-windowed snapshots of the whistler wave radiation patterns are shown to provide a remote diagnostic of the cross-field speed of the laser-produced plasma.

  14. Clustering-Triggered Emission of Nonconjugated Polyacrylonitrile.

    Science.gov (United States)

    Zhou, Qing; Cao, Boyu; Zhu, Chenxuan; Xu, Si; Gong, Yongyang; Yuan, Wang Zhang; Zhang, Yongming

    2016-12-01

    Intrinsic emission from nonconjugated polymers has attracted considerable attention owing to its fundamental importance and intensive applications in diverse fields. The emission mechanism, however, is still in debate. Herein, nonconjugated polyacrylonitrile (PAN) molecules are found to be virtually nonluminescent in dilute solutions, while being highly emissive when concentrated or aggregated as nanosuspensions, solid powders, and films, exhibiting distinct aggregation-induced emission (AIE) characteristics. Moreover, triplet emissions of delayed fluorescence and room temperature phosphorescence are detected from the solid powders. Such unique emission of nonconjugated PAN is ascribed to the formation of cyano clusters, which act as the exact chromophores. In these clusters, through space electronic interactions, namely overlap of π and lone pair (n) electrons among cyano groups extend the conjugation and meanwhile rigidify the molecular conformations, thus offering remarkable emission upon irradiation. The AIE phenomenon can also be well rationalized by the formation of cyano clusters together with conformation rigidification. And the triplet emissions shall be originated from the n-π* transition owing to the presence of lone pairs. It is believed that such clustering-triggered emission mechanism is instructive for further development of unorthodox luminogens. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Cyclotron Acceleration of Relativistic Electrons through Landau Resonance with Obliquely Propagating Whistler Mode Chorus Emissions

    Science.gov (United States)

    Omura, Y.; Hsieh, Y. K.; Foster, J. C.; Erickson, P. J.; Kletzing, C.; Baker, D. N.

    2017-12-01

    A recent test particle simulation of obliquely propagating whistler mode wave-particle interaction [Hsieh and Omura, 2017] shows that the perpendicular wave electric field can play a significant role in trapping and accelerating relativistic electrons through Landau resonance. A further theoretical and numerical investigation verifies that there occurs nonlinear wave trapping of relativistic electrons by the nonlinear Lorentz force of the perpendicular wave magnetic field. An electron moving with a parallel velocity equal to the parallel phase velocity of an obliquely propagating wave basically see a stationary wave phase. Since the electron position is displaced from its gyrocenter by a distance ρ*sin(φ), where ρ is the gyroradius and φ is the gyrophase, the wave phase is modulated with the gyromotion, and the stationary wave fields as seen by the electron are expanded as series of Bessel functions Jn with phase variations n*φ. The J1 components of the wave electric and magnetic fields rotate in the right-hand direction with the gyrofrequency, and they can be in resonance with the electron undergoing the gyromotion, resulting in effective electron acceleration and pitch angle scattering. We have performed a subpacket analysis of chorus waveforms observed by the Van Allen Probes [Foster et al., 2017], and calculated the energy gain by the cyclotron acceleration through Landau resonance. We compare the efficiencies of accelerations by cyclotron and Landau resonances in typical events of rapid electron acceleration observed by the Van Allen Probes.References:[1] Hsieh, Y.-K., and Y. Omura (2017), Nonlinear dynamics of electrons interacting with oblique whistler mode chorus in the magnetosphere, J. Geophys. Res. Space Physics, 122, 675-694, doi:10.1002/2016JA023255.[2] Foster, J. C., P. J. Erickson, Y. Omura, D. N. Baker, C. A. Kletzing, and S. G. Claudepierre (2017), Van Allen Probes observations of prompt MeV radiation belt electron acceleration in nonlinear

  16. EMIC triggered chorus emissions in Cluster data

    Czech Academy of Sciences Publication Activity Database

    Grison, Benjamin; Santolík, Ondřej; Cornilleau-Wehrlin, N.; Masson, A.; Engebretson, M. J.; Pickett, J. S.; Omura, Y.; Robert, P.; Nomura, R.

    2013-01-01

    Roč. 118, č. 3 (2013), s. 1159-1169 ISSN 2169-9380 R&D Projects: GA MŠk 7E12026; GA ČR(CZ) GPP209/11/P848; GA ČR GAP205/10/2279; GA MŠk(CZ) LH11122 EU Projects: European Commission(XE) 284520 - MAARBLE Program:FP7 Institutional support: RVO:68378289 Keywords : EMIC wave * triggered emission * plasmapause Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/jgra.50178/abstract

  17. Mapping lightning discharges on Earth with lightning-generated whistlers wave emission in space and their effects on radiation belt electrons

    Science.gov (United States)

    Farges, T.; Ripoll, J. F.; Santolik, O.; Kolmasova, I.; Kurth, W. S.; Hospodarsky, G. B.; Kletzing, C.

    2017-12-01

    It is widely accepted that the slot region of the Van Allen radiation belts is sculpted by the presence of whistler mode waves especially by plasmaspheric hiss emissions. In this work, we investigate the role of lightning-generated whistler waves (LGW), which also contribute to scatter electrons trapped in the plasmaphere but, in general, to a lesser extent due to their low mean amplitude and occurrence rate. Our goal is to revisit the characterization of LGW occurrence in the Earth's atmosphere and in space as well as the computation of LGW effects by looking at a series of particular events, among which intense events, in order to characterize maximal scattering effects. We use multicomponent measurements of whistler mode waves by the Waves instrument of Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) onboard the Van Allen Probes spacecraft as our primary data source. We combine this data set with local measurements of the plasma density. We also use the data of the World Wide Lightning Location Network in order to localize the source of lightning discharges on Earth and their radiated energy, both locally at the footprint of the spacecraft and, globally, along the drift path. We discuss how to relate the signal measured in space with the estimation of the power emitted in the atmosphere and the associated complexity. Using these unique data sets we model the coefficients of quasi-linear pitch angle diffusion and we estimate effects of these waves on radiation belt electrons. We show evidence that lightning generated whistlers can, at least in some cases, influence the radiation belt dynamics.

  18. Influence of lightning generated whistlers on radiation belt losses in the plasmasphere.

    Science.gov (United States)

    Santolik, O.; Ripoll, J. F.; Farges, T.; Kolmasova, I.; Kurth, W. S.; Hospodarsky, G. B.; Kletzing, C.

    2016-12-01

    It is widely accepted that the slot region of the Van Allen radiation belts is sculpted by the presence of whistler mode waves, especially by plasmaspheric hiss emissions. Substantial evidence exists that plasmaspheric hiss itself can arise from strong emissions of whistler-mode chorus, generated in the outer zone equatorial region and propagated to high latitudes and inward, filling thus the plasmasphere and forming hiss. However the debate on the origin of hiss is still open to other possibilities: local generation and accumulation or triggering by lightning generated whistlers. We show evidence that the latter possibility can play a role and that lightning generated whistlers can, at least in some cases, influence the radiation belt dynamics. We use multicomponent measurements of whistlers and hiss by the Waves instrument of Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) onboard the Van Allen Probes spacecraft as our primary data source. We combine this data set with local measurements of the plasma density based on the determination of the upper hybrid resonance frequency and with the data of the World Wide Lightning Location Network which are used to localize the source lightning discharges and their radiated energy. Using these unique data sets we model the coefficients of quasi-linear pitch angle diffusion and we estimate effects of these waves on the decay rates of radiation belt electrons.

  19. Nonlinear electron magnetohydrodynamics physics. IV. Whistler instabilities

    International Nuclear Information System (INIS)

    Urrutia, J. M.; Stenzel, R. L.; Strohmaier, K. D.

    2008-01-01

    A very large low-frequency whistler mode is excited with magnetic loop antennas in a uniform laboratory plasma. The wave magnetic field exceeds the ambient field causing in one polarity a field reversal, and a magnetic topology resembling that of spheromaks in the other polarity. These propagating ''whistler spheromaks'' strongly accelerate the electrons and create non-Maxwellian distributions in their toroidal current ring. It is observed that the locally energized electrons in the current ring excite new electromagnetic instabilities and emit whistler modes with frequencies unrelated to the applied frequency. Emissions are also observed from electrons excited in X-type neutral lines around the antenna. The properties of the excited waves such as amplitudes, frequency spectra, field topologies, propagation, polarization, growth, and damping have been investigated. The waves remain linear (B wave 0 ) and convert a small part of the electron kinetic energy into wave magnetic energy (B wave 2 /2μ 0 e )

  20. Cluster observations of reflected EMIC-triggered emission

    Czech Academy of Sciences Publication Activity Database

    Grison, Benjamin; Darrouzet, F.; Santolík, Ondřej; Cornilleau-Wehrlin, N.; Masson, A.

    2016-01-01

    Roč. 43, č. 9 (2016), s. 4164-4171 ISSN 0094-8276 R&D Projects: GA ČR(CZ) GAP209/12/2394; GA MŠk(CZ) LH15304 Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : EMIC * triggered emission * wave reflection * plasmapause Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.253, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2016GL069096/full

  1. Multiflash whistlers in ELF-band observed at low latitude

    Directory of Open Access Journals (Sweden)

    A. K. Singh

    2011-01-01

    Full Text Available Multiflash whistler-like event in the ELF-band, observed during March 1998 at low latitude station Jammu, is reported. The most prominent feature of these events is the multiflash nature along with the decrease in frequency within a very short span of time resembling similar to terrestrial whistlers. The events have a significantly smaller time duration (0.5–3.5 s than those reported earlier from high, mid and low latitudes and also display a diurnal maximum occurring around 09:30 h (IST. There have been similar reportings from other latitudes, but whistlers in the ELF-band with a multiflash nature along with a precursor emission have never been reported. Lightning seems to be the dominant source for the ELF whistlers reported here.

  2. Whistlers and related ionospheric phenomena

    CERN Document Server

    Helliwell, Robert A

    2006-01-01

    The investigation of whistlers and related phenomena is a key element in studies of very-low-frequency propagation, satellite communication, the outer ionosphere, and solar-terrestrial relationships. This comprehensive text presents a history of the study of the phenomena and includes all the elements necessary for the calculation of the characteristics of whistlers and whistler-mode signals.An introduction and brief history are followed by a summary of the theory of whistlers and a detailed explanation of the calculation of their characteristics. Succeeding chapters offer a complete atlas of

  3. On the gyro resonance electron-whistler interaction in transition layers of near-earth plasma

    International Nuclear Information System (INIS)

    Erokhin, N.S.; Zol'nikova, N.N.; Mikhajlovskaya, L.A.

    1996-01-01

    Gyro resonance interaction of electrons with low amplitude triggered whistler in the transition layers of the ionospheric and magnetospheric plasma that correspond to the blurred jumps of the magnetic field and plasma concentration was studied

  4. Source Region Identification for Low Latitude Whistlers (L=1.08)

    Science.gov (United States)

    Gokani, S. A.; Singh, R.; Maurya, A. K.; Bhaskara, V.; Cohen, M.; Kumar, S.; Lichtenberger, J.

    2014-12-01

    Though whistlers are known and studied from past one century, the scientific community still strives to understand the generation and propagation mechanism of whistlers in very low latitude region. One of the solutions comes from locating the causative lightning discharges and source region of low latitude whistlers. In the present study, ~ 2000 whistlers recorded during period of one year (Dec, 2010 to Jan, 2011) at Allahabad (Geomag. lat. 16.79o N; L=1.08), India are correlated with lightning activity detected by World Wide Lightning Location Network (WWLLN) at and around conjugate region. About 63% of whistlers are correlated with the lightning strikes around conjugate region. Further to confirm this correlation, arrival azimuths of causative sferics are determined and the obtained azimuths points towards conjugate region of Allahabad. The characteristics of thunder cloud generating these whistlers are examined and found that the clouds with South-East alignment are more prone to trigger whistler waves. The seasonal and diurnal variation of whistler parameters such as occurrence rate, power spectral density and dispersion are also studied and explained on the basis of ionospheric conditions in low latitudes. The results obtained open a new window to look for the propagation mechanism of low latitude whistlers.

  5. Synchronized whistlers recorded at Varanasi

    Indian Academy of Sciences (India)

    An attempt has been made to explain the dynamic spectra using lightning discharge generated from magnetospheric sources. Keywords. Whistler-mode wave propagation; dispersion; synchronized whistler. PACS No. 94.20.Mm. It is well-known that electromagnetic waves in wide frequency range are associated with.

  6. Synchronized whistlers recorded at Varanasi

    Indian Academy of Sciences (India)

    ... during magnetic storm period of the year 1977 are presented. The dynamic spectrum analysis shows that the component whistlers are Eckersley whistlers having dispersion 10 s1/2 and 30 s1/2. An attempt has been made to explain the dynamic spectra using lightning discharge generated from magnetospheric sources.

  7. Resonant scattering of energetic electrons in the plasmasphere by monotonic whistler-mode waves artificially generated by ionospheric modification

    Directory of Open Access Journals (Sweden)

    S. S. Chang

    2014-05-01

    Full Text Available Modulated high-frequency (HF heating of the ionosphere provides a feasible means of artificially generating extremely low-frequency (ELF/very low-frequency (VLF whistler waves, which can leak into the inner magnetosphere and contribute to resonant interactions with high-energy electrons in the plasmasphere. By ray tracing the magnetospheric propagation of ELF/VLF emissions artificially generated at low-invariant latitudes, we evaluate the relativistic electron resonant energies along the ray paths and show that propagating artificial ELF/VLF waves can resonate with electrons from ~ 100 keV to ~ 10 MeV. We further implement test particle simulations to investigate the effects of resonant scattering of energetic electrons due to triggered monotonic/single-frequency ELF/VLF waves. The results indicate that within the period of a resonance timescale, changes in electron pitch angle and kinetic energy are stochastic, and the overall effect is cumulative, that is, the changes averaged over all test electrons increase monotonically with time. The localized rates of wave-induced pitch-angle scattering and momentum diffusion in the plasmasphere are analyzed in detail for artificially generated ELF/VLF whistlers with an observable in situ amplitude of ~ 10 pT. While the local momentum diffusion of relativistic electrons is small, with a rate of −7 s−1, the local pitch-angle scattering can be intense near the loss cone with a rate of ~ 10−4 s−1. Our investigation further supports the feasibility of artificial triggering of ELF/VLF whistler waves for removal of high-energy electrons at lower L shells within the plasmasphere. Moreover, our test particle simulation results show quantitatively good agreement with quasi-linear diffusion coefficients, confirming the applicability of both methods to evaluate the resonant diffusion effect of artificial generated ELF/VLF whistlers.

  8. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The hardware of the trigger components has been mostly finished. The ECAL Endcap Trigger Concentrator Cards (TCC) are in production while Barrel TCC firmware has been upgraded, and the Trigger Primitives can now be stored by the Data Concentrator Card for readout by the DAQ. The Regional Calorimeter Trigger (RCT) system is complete, and the timing is being finalized. All 502 HCAL trigger links to RCT run without error. The HCAL muon trigger timing has been equalized with DT, RPC, CSC and ECAL. The hardware and firmware for the Global Calorimeter Trigger (GCT) jet triggers are being commissioned and data from these triggers is available for readout. The GCT energy sums from rings of trigger towers around the beam pipe beam have been changed to include two rings from both sides. The firmware for Drift Tube Track Finder, Barrel Sorter and Wedge Sorter has been upgraded, and the synchronization of the DT trigger is satisfactory. The CSC local trigger has operated flawlessly u...

  9. TRIGGER

    CERN Multimedia

    Roberta Arcidiacono

    2013-01-01

    Trigger Studies Group (TSG) The Trigger Studies Group has just concluded its third 2013 workshop, where all POGs presented the improvements to the physics object reconstruction, and all PAGs have shown their plans for Trigger development aimed at the 2015 High Level Trigger (HLT) menu. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger menu development, path timing, Trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – this last task in collaboration with PdmV (Physics Data and Monte Carlo Validation group). In the last months the group has delivered several HLT rate estimates and comparisons, using the available data and Monte Carlo samples. The studies were presented at the Trigger workshops in September and December, and STEAM has contacted POGs and PAGs to understand the origin of the discrepancies observed between 8 TeV data and Monte Carlo simulations. The most recent results show what the...

  10. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The trigger synchronization procedures for running with cosmic muons and operating with the LHC were reviewed during the May electronics week. Firmware maintenance issues were also reviewed. Link tests between the new ECAL endcap trigger concentrator cards (TCC48) and the Regional Calorimeter Trigger have been performed. Firmware for the energy sum triggers and an upgraded tau trigger of the Global Calorimeter Triggers has been developed and is under test. The optical fiber receiver boards for the Track-Finder trigger theta links of the DT chambers are now all installed. The RPC trigger is being made more robust by additional chamber and cable shielding and also by firmware upgrades. For the CSC’s the front-end and trigger motherboard firmware have been updated. New RPC patterns and DT/CSC lookup tables taking into account phi asymmetries in the magnetic field configuration are under study. The motherboard for the new pipeline synchronizer of the Global Trigg...

  11. TRIGGER

    CERN Multimedia

    W. Smith

    2012-01-01

      Level-1 Trigger The Level-1 Trigger group is ready to deploy improvements to the L1 Trigger algorithms for 2012. These include new high-PT patterns for the RPC endcap, an improved CSC PT assignment, a new PT-matching algorithm for the Global Muon Trigger, and new calibrations for ECAL, HCAL, and the Regional Calorimeter Trigger. These should improve the efficiency, rate, and stability of the L1 Trigger. The L1 Trigger group also is migrating the online systems to SLC5. To make the data transfer from the Global Calorimeter Trigger to the Global Trigger more reliable and also to allow checking the data integrity online, a new optical link system has been developed by the GCT and GT groups and successfully tested at the CMS electronics integration facility in building 904. This new system is now undergoing further tests at Point 5 before being deployed for data-taking this year. New L1 trigger menus have recently been studied and proposed by Emmanuelle Perez and the L1 Detector Performance Group...

  12. TRIGGER

    CERN Multimedia

    W. Smith

    At the March meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, the program of trigger pattern tests and vertical slice tests and planning for the Global Runs starting this summer. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and integration testing is in full swing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. After full checkout, trigger subsystems will be then operated in the CMS Global Runs. Continuous...

  13. TRIGGER

    CERN Multimedia

    by Wesley Smith

    2010-01-01

    Level-1 Trigger Hardware and Software The overall status of the L1 trigger has been excellent and the running efficiency has been high during physics fills. The timing is good to about 1%. The fine-tuning of the time synchronization of muon triggers is ongoing and will be completed after more than 10 nb-1 of data have been recorded. The CSC trigger primitive and RPC trigger timing have been refined. A new configuration for the CSC Track Finder featured modified beam halo cuts and improved ghost cancellation logic. More direct control was provided for the DT opto-receivers. New RPC Cosmic Trigger (RBC/TTU) trigger algorithms were enabled for collision runs. There is further work planned during the next technical stop to investigate a few of the links from the ECAL to the Regional Calorimeter Trigger (RCT). New firmware and a new configuration to handle trigger rate spikes in the ECAL barrel are also being tested. A board newly developed by the tracker group (ReTRI) has been installed and activated to block re...

  14. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The production of the trigger hardware is now basically finished, and in time for the turn-on of the LHC. The last boards produced are the Trigger Concentrator Cards for the ECAL Endcaps (TCC-EE). After the recent installation of the four EE Dees, the TCC-EE prototypes were used for their commissioning. Production boards are arriving and are being tested continuously, with the last ones expected in November. The Regional Calorimeter Trigger hardware is fully integrated after installation of the last EE cables. Pattern tests from the HCAL up to the GCT have been performed successfully. The HCAL triggers are fully operational, including the connection of the HCAL-outer and forward-HCAL (HO/HF) technical triggers to the Global Trigger. The HCAL Trigger and Readout (HTR) board firmware has been updated to permit recording of the tower “feature bit” in the data. The Global Calorimeter Trigger hardware is installed, but some firmware developments are still n...

  15. TRIGGER

    CERN Multimedia

    W. Smith

    2010-01-01

    Level-1 Trigger Hardware and Software The Level-1 Trigger hardware has performed well during both the recent proton-proton and heavy ion running. Efforts were made to improve the visibility and handling of alarms and warnings. The tracker ReTRI boards that prevent fixed frequencies of Level-1 Triggers are now configured through the Trigger Supervisor. The Global Calorimeter Trigger (GCT) team has introduced a buffer cleanup procedure at stops and a reset of the QPLL during configuring to ensure recalibration in case of a switch from the LHC clock to the local clock. A device to test the cables between the Regional Calorimeter Trigger and the GCT has been manufactured. A wrong charge bit was fixed in the CSC Trigger. The ECAL group is improving crystal masking and spike suppression in the trigger primitives. New firmware for the Drift Tube Track Finder (DTTF) sorters was developed to improve fake track tagging and sorting. Zero suppression was implemented in the DT Sector Collector readout. The track finder b...

  16. TRIGGER

    CERN Multimedia

    Wesley Smith

    Trigger Hardware The status of the trigger components was presented during the September CMS Week and Annual Review and at the monthly trigger meetings in October and November. Procedures for cold and warm starts (e.g. refreshing of trigger parameters stored in registers) of the trigger subsystems have been studied. Reviews of parts of the Global Calorimeter Trigger (GCT) and the Global Trigger (GT) have taken place in October and November. The CERN group summarized the status of the Trigger Timing and Control (TTC) system. All TTC crates and boards are installed in the underground counting room, USC55. The central clock system will be upgraded in December (after the Global Run at the end of November GREN) to the new RF2TTC LHC machine interface timing module. Migration of subsystem's TTC PCs to SLC4/ XDAQ 3.12 is being prepared. Work is on going to unify the access to Local Timing Control (LTC) and TTC CMS interface module (TTCci) via SOAP (Simple Object Access Protocol, a lightweight XML-based messaging ...

  17. TRIGGER

    CERN Multimedia

    W. Smith from contributions of C. Leonidopoulos

    2010-01-01

    Level-1 Trigger Hardware and Software Since nearly all of the Level-1 (L1) Trigger hardware at Point 5 has been commissioned, activities during the past months focused on the fine-tuning of synchronization, particularly for the ECAL and the CSC systems, on firmware upgrades and on improving trigger operation and monitoring. Periodic resynchronizations or hard resets and a shortened luminosity section interval of 23 seconds were implemented. For the DT sector collectors, an automatic power-off was installed in case of high temperatures, and the monitoring capabilities of the opto-receivers and the mini-crates were enhanced. The DTTF and the CSCTF now have improved memory lookup tables. The HCAL trigger primitive logic implemented a new algorithm providing better stability of the energy measurement in the presence of any phase misalignment. For the Global Calorimeter Trigger, additional Source Cards have been manufactured and tested. Testing of the new tau, missing ET and missing HT algorithms is underw...

  18. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware and Software The trigger system has been constantly in use in cosmic and commissioning data taking periods. During CRAFT running it delivered 300 million muon and calorimeter triggers to CMS. It has performed stably and reliably. During the abort gaps it has also provided laser and other calibration triggers. Timing issues, namely synchronization and latency issues, have been solved. About half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are installed, and the firmware is being worked on. The production of the other half has started. The HCAL Trigger and Readout (HTR) card firmware has been updated, and new features such as fast parallel zero-suppression have been included. Repairs of drift tube (DT) trigger mini-crates, optical links and receivers of sector collectors are under way and have been completed on YB0. New firmware for the optical receivers of the theta links to the drift tube track finder is being installed. In parallel, tests with new eta track finde...

  19. TRIGGER

    CERN Multimedia

    R. Carlin with contributions from D. Acosta

    2012-01-01

    Level-1 Trigger Data-taking continues at cruising speed, with high availability of all components of the Level-1 trigger. We have operated the trigger up to a luminosity of 7.6E33, where we approached 100 kHz using the 7E33 prescale column.  Recently, the pause without triggers in case of an automatic "RESYNC" signal (the "settle" and "recover" time) was reduced in order to minimise the overall dead-time. This may become very important when the LHC comes back with higher energy and luminosity after LS1. We are also preparing for data-taking in the proton-lead run in early 2013. The CASTOR detector will make its comeback into CMS and triggering capabilities are being prepared for this. Steps to be taken include improved cooperation with the TOTEM trigger system and using the LHC clock during the injection and ramp phases of LHC. Studies are being finalised that will have a bearing on the Trigger Technical Design Report (TDR), which is to be rea...

  20. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The final parts of the Level-1 trigger hardware are now being put in place. For the ECAL endcaps, more than half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are now available at CERN, such that one complete endcap can be covered. The Global Trigger now correctly handles ECAL calibration sequences, without being influenced by backpressure. The Regional Calorimeter Trigger (RCT) hardware is complete and working in USC55. Intra-crate tests of all 18 RCT crates and the Global Calorimeter Trigger (GCT) are regularly taking place. Pattern tests have successfully captured data from HCAL through RCT to the GCT Source Cards. HB/HE trigger data are being compared with emulator results to track down the very few remaining hardware problems. The treatment of hot and dead cells, including their recording in the database, has been defined. For the GCT, excellent agreement between the emulator and data has been achieved for jets and HF ET sums. There is still som...

  1. TRIGGER

    CERN Multimedia

    W. Smith

    At the December meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, and results from the Magnet Test and Cosmic Challenge (MTCC) phase II. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and moving towards integration testing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. This is combined with operations and testing without beam that will continue until startup. The plans for start-up, pilot and early running tri...

  2. TRIGGER

    CERN Multimedia

    W. Smith, from contributions of D. Acosta

    2012-01-01

      The L1 Trigger group deployed several major improvements this year. Compared to 2011, the single-muon trigger rate has been reduced by a factor of 2 and the η coverage has been restored to 2.4, with high efficiency. During the current technical stop, a higher jet seed threshold will be applied in the Global Calorimeter Trigger in order to significantly reduce the strong pile-up dependence of the HT and multi-jet triggers. The currently deployed L1 menu, with the “6E33” prescales, has a total rate of less than 100 kHz and operates with detector readout dead time of less than 3% for luminosities up to 6.5 × 1033 cm–2s–1. Further prescale sets have been created for 7 and 8 × 1033 cm–2s–1 luminosities. The L1 DPG is evaluating the performance of the Trigger for upcoming conferences and publication. Progress on the Trigger upgrade was reviewed during the May Upgrade Week. We are investigating scenarios for stagin...

  3. TRIGGER

    CERN Multimedia

    Wesley Smith

    2011-01-01

    Level-1 Trigger Hardware and Software New Forward Scintillating Counters (FSC) for rapidity gap measurements have been installed and integrated into the Trigger recently. For the Global Muon Trigger, tuning of quality criteria has led to improvements in muon trigger efficiencies. Several subsystems have started campaigns to increase spares by recovering boards or producing new ones. The barrel muon sector collector test system has been reactivated, new η track finder boards are in production, and φ track finder boards are under revision. In the CSC track finder, an η asymmetry problem has been corrected. New pT look-up tables have also improved efficiency. RPC patterns were changed from four out of six coincident layers to three out of six in the barrel, which led to a significant increase in efficiency. A new PAC firmware to trigger on heavy stable charged particles allows looking for chamber hit coincidences in two consecutive bunch-crossings. The redesign of the L1 Trigger Emulator...

  4. TRIGGER

    CERN Multimedia

    R. Arcidiacono

    2013-01-01

      In 2013 the Trigger Studies Group (TSG) has been restructured in three sub-groups: STEAM, for the development of new HLT menus and monitoring their performance; STORM, for the development of HLT tools, code and actual configurations; and FOG, responsible for the online operations of the High Level Trigger. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger Menu development, path timing, trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – in collaboration and with the technical support of the PdmV group. Since the end of proton-proton data taking, the group has started preparing for 2015 data taking, with collisions at 13 TeV and 25 ns bunch spacing. The reliability of the extrapolation to higher energy is being evaluated comparing the trigger rates on 7 and 8 TeV Monte Carlo samples with the data taken in the past two years. The effect of 25 ns bunch spacing is being studied on the d...

  5. TRIGGER

    CERN Multimedia

    W. Smith from contributions of C. Leonidopoulos, I. Mikulec, J. Varela and C. Wulz.

    Level-1 Trigger Hardware and Software Over the past few months, the Level-1 trigger has successfully recorded data with cosmic rays over long continuous stretches as well as LHC splash events, beam halo, and collision events. The L1 trigger hardware, firmware, synchronization, performance and readiness for beam operation were reviewed in October. All L1 trigger hardware is now installed at Point 5, and most of it is completely commissioned. While the barrel ECAL Trigger Concentrator Cards are fully operational, the recently delivered endcap ECAL TCC system is still being commissioned. For most systems there is a sufficient number of spares available, but for a few systems additional reserve modules are needed. It was decided to increase the overall L1 latency by three bunch crossings to increase the safety margin for trigger timing adjustments. In order for CMS to continue data taking during LHC frequency ramps, the clock distribution tree needs to be reset. The procedures for this have been tested. A repl...

  6. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware and Software The road map for the final commissioning of the level-1 trigger system has been set. The software for the trigger subsystems is being upgraded to run under CERN Scientific Linux 4 (SLC4). There is also a new release for the Trigger Supervisor (TS 1.4), which implies upgrade work by the subsystems. As reported by the CERN group, a campaign to tidy the Trigger Timing and Control (TTC) racks has begun. The machine interface was upgraded by installing the new RF2TTC module, which receives RF signals from LHC Point 4. Two Beam Synchronous Timing (BST) signals, one for each beam, can now be received in CMS. The machine group will define the exact format of the information content shortly. The margin on the locking range of the CMS QPLL is planned for study for different subsystems in the next Global Runs, using a function generator. The TTC software has been successfully tested on SLC4. Some TTC subsystems have already been upgraded to SLC4. The TTCci Trigger Supervisor ...

  7. TRIGGER

    CERN Multimedia

    W. Smith

    2011-01-01

    Level-1 Trigger Hardware and Software Overall the L1 trigger hardware has been running very smoothly during the last months of proton running. Modifications for the heavy-ion run have been made where necessary. The maximal design rate of 100 kHz can be sustained without problems. All L1 latencies have been rechecked. The recently installed Forward Scintillating Counters (FSC) are being used in the heavy ion run. The ZDC scintillators have been dismantled, but the calorimeter itself remains. We now send the L1 accept signal and other control signals to TOTEM. Trigger cables from TOTEM to CMS will be installed during the Christmas shutdown, so that the TOTEM data can be fully integrated within the CMS readout. New beam gas triggers have been developed, since the BSC-based trigger is no longer usable at high luminosities. In particular, a special BPTX signal is used after a quiet period with no collisions. There is an ongoing campaign to provide enough spare modules for the different subsystems. For example...

  8. TRIGGER

    CERN Multimedia

    J. Alimena

    2013-01-01

    Trigger Strategy Group The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for the development of future High-Level Trigger menus, as well as of its DQM and validation, in collaboration and with the technical support of the PdmV group. Taking into account the beam energy and luminosity expected in 2015, a rough estimate of the trigger rates indicates a factor four increase with respect to 2012 conditions. Assuming that a factor two can be tolerated thanks to the increase in offline storage and processing capabilities, a toy menu has been developed using the new OpenHLT workflow to estimate the transverse energy/momentum thresholds that would halve the current trigger rates. The CPU time needed to run the HLT has been compared between data taken with 25 ns and 50 ns bunch spacing, for equivalent pile-up: no significant difference was observed on the global time per event distribution at the only available data point, corresponding to a pile-up of about 10 interactions. Using th...

  9. TRIGGER

    CERN Multimedia

    by Wesley Smith

    2011-01-01

    Level-1 Trigger Hardware and Software After the winter shutdown minor hardware problems in several subsystems appeared and were corrected. A reassessment of the overall latency has been made. In the TTC system shorter cables between TTCci and TTCex have been installed, which saved one bunch crossing, but which may have required an adjustment of the RPC timing. In order to tackle Pixel out-of-syncs without influencing other subsystems, a special hardware/firmware re-sync protocol has been introduced in the Global Trigger. The link between the Global Calorimeter Trigger and the Global Trigger with the new optical Global Trigger Interface and optical receiver daughterboards has been successfully tested in the Electronics Integration Centre in building 904. New firmware in the GCT now allows a setting to remove the HF towers from energy sums. The HF sleeves have been replaced, which should lead to reduced rates of anomalous signals, which may allow their inclusion after this is validated. For ECAL, improvements i...

  10. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware The CERN group is working on the TTC system. Seven out of nine sub-detector TTC VME crates with all fibers cabled are installed in USC55. 17 Local Trigger Controller (LTC) boards have been received from production and are in the process of being tested. The RF2TTC module replacing the TTCmi machine interface has been delivered and will replace the TTCci module used to mimic the LHC clock. 11 out of 12 crates housing the barrel ECAL off-detector electronics have been installed in USC55 after commissioning at the Electronics Integration Centre in building 904. The cabling to the Regional Calorimeter Trigger (RCT) is terminated. The Lisbon group has completed the Synchronization and Link mezzanine board (SLB) production. The Palaiseau group has fully tested and installed 33 out of 40 Trigger Concentrator Cards (TCC). The seven remaining boards are being remade. The barrel TCC boards have been tested at the H4 test beam, and good agreement with emulator predictions were found. The cons...

  11. Synchronized whistlers recorded at Varanasi

    Indian Academy of Sciences (India)

    [10] M J Rycroft, A review of whistlers and energetic electron precipitations, Review of Radio. Sciences edited by W R Stone, 1990-1992 URSI (Oxford University Press, Oxford, 1993) p. 631. [11] V Y Trakhtengertz and M J Rycroft, J. Atmos. Solar Terr. Phys. 62 (2000). [12] W C Armstrong, Nature (London) 327, 405 (1987).

  12. Pitch Angle Scattering of Upgoing Electron Beams in Jupiter's Polar Regions by Whistler Mode Waves

    Science.gov (United States)

    Elliott, S. S.; Gurnett, D. A.; Kurth, W. S.; Clark, G.; Mauk, B. H.; Bolton, S. J.; Connerney, J. E. P.; Levin, S. M.

    2018-02-01

    The Juno spacecraft's Jupiter Energetic-particle Detector Instrument has observed field-aligned, unidirectional (upgoing) electron beams throughout most of Jupiter's entire polar cap region. The Waves instrument detected intense broadband whistler mode emissions occurring in the same region. In this paper, we investigate the pitch angle scattering of the upgoing electron beams due to interactions with the whistler mode waves. Profiles of intensity versus pitch angle for electron beams ranging from 2.53 to 7.22 Jovian radii show inconsistencies with the expected adiabatic invariant motion of the electrons. It is believed that the observed whistler mode waves perturb the electron motion and scatter them away from the magnetic field line. The diffusion equation has been solved by using diffusion coefficients which depend on the magnetic intensity of the whistler mode waves.

  13. Initial search for triggered gamma emission from Hf-178(m2) using the YSU miniball array

    Czech Academy of Sciences Publication Activity Database

    Carroll, J. J.; Burnett, J.; Drummond, T.; Lepak, J.; Propri, R.; Smith, D.; Karamian, S. A.; Adam, Jindřich; Stedile, F.; Agee, FJ.

    2002-01-01

    Roč. 143, 1, 2, 3, 4 (2002), s. 37-54 ISSN 0304-3843 Institutional research plan: CEZ:AV0Z1048901 Keywords : triggered gamma emission * Hf-178(m2) * nuclear batteries Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.533, year: 2002

  14. First direct observation of runaway electron-driven whistler waves in tokamaks

    Science.gov (United States)

    Spong, Donald A.

    2017-10-01

    Whistlers are electromagnetic waves that can be driven unstable by energetic electrons and are observed in natural plasmas, such as the ionosphere and Van Allen belts. Recent DIII-D experiments at low density demonstrate the first direct observation of whistlers in tokamaks, with 100-200 MHz waves excited by runaway electrons (REs) in the multi-MeV range. Whistler activity is correlated with RE intensity and the frequencies scale with magnetic field strength and electron density consistent with a whistler dispersion relation. Fluctuations occur in discrete frequency bands, and not a continuum as would be expected from plane wave analysis, suggesting the important role of toroidicity. An MHD model including the bounded/periodic nature of the plasma identifies multiple eigenmode branches. For a toroidal mode number n = 10, the predicted frequencies and spacing are similar to observations. The instabilities are stabilized with increasing magnetic field, as expected from the anomalous Doppler resonance. The whistler amplitudes show intermittent time variations. Predator-prey cycles with electron cyclotron emission (ECE) signals are observed, which can be interpreted as wave-induced pitch angle scattering of moderate energy REs. Such nonlinear dynamics are supported by quasi-linear simulations indicating that REs are scattered both by whistlers and high frequency magnetized plasma waves. The whistler wave predominantly scatters the high energy REs, while the magnetized plasma wave scatters the low energy REs, abruptly enhancing the ECE signal. Amplitude variations are also associated with sawtooth activity, indicating that the REs sample the q = 1 surface. These features of the RE-driven whistler have connections to ionospheric plasmas and open up new directions for the modeling and active control of tokamak REs. Work supported by the US DOE under DE-FC02-04ER54698, DE-AC52-07NA27344, DE-FG02-07ER54917, DE-SC00-16268, and DE-AC05-00OR22725.

  15. Observations of unusual whistlers during daytime at Jammu

    Indian Academy of Sciences (India)

    1999-03-08

    spectra of these events is briefly presented. 1. Introduction. Whistler ... tude whistlers and the determination of various plasma parameters in .... (Date of whistler recording March 8, 1999). Total. Time of. Equatorial electron observation. Nose electron content NT hours. Dispersion frequency density. 10. 13 el/(cm. 2. Whistler.

  16. Chasing Lightning: Sferics, Tweeks and Whistlers

    Science.gov (United States)

    Webb, P. A.; Franzen, K.; Garcia, L.; Schou, P.; Rous, P.

    2008-12-01

    We all know what lightning looks like during a thunderstorm, but the visible flash we see is only part of the story. This is because lightning also generates light with other frequencies that we cannot perceive with our eyes, but which are just as real as visible light. Unlike the visible light from lightning, these other frequencies can carry the lightning's energy hundreds or thousands of miles across the surface of the Earth in the form of special signals called "tweeks" and "sferics". Some of these emissions can even travel tens of thousands of miles out into space before returning to the Earth as "whistlers". The INSPIRE Project, Inc is a non-profit scientific and educational corporation whose beginning mission was to bring the excitement of observing these very low frequency (VLF) natural radio waves emissions from lightning to high school students. Since 1989, INSPIRE has provided specially designed radio receiver kits to over 2,600 participants around the world to make observations of signals in the VLF frequency range. Many of these participants are using the VLF data they collect in very creative projects that include fiction, music and art exhibitions. During the Fall 2008 semester, the first INSPIRE based university-level course was taught at University of Maryland Baltimore County (UMBC) as part of its First-Year Seminar (FYS) series. The FYS classes are limited to 20 first-year students per class and are designed to create an active-learning environment that encourages student participation and discussion that might not otherwise occur in larger first-year classes. This presentation will cover the experiences gained from using the INSPIRE kits as the basis of a university course. This will include the lecture material that covers the basic physics of lightning, thunderstorms and the Earth's atmosphere, as well as the electronics required to understand the basic workings of the VLF kit. It will also cover the students assembly of the kit in an

  17. Lower Hybrid to Whistler Wave Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Winske, Dan [Los Alamos National Laboratory

    2012-07-16

    In this presentation we discuss recent work concerning the conversion of whistler waves to lower hybrid waves (as well as the inverse process). These efforts have been motivated by the issue of attenuation of upward propagating whistler waves in the ionosphere generated by VLF transmitters on the ground, i.e., the 'Starks 20 db' problem, which affects the lifetimes of energetic electrons trapped in the geomagnetic field at low magnetic altitude (L). We discuss recent fluid and kinetic plasma simulations as well as ongoing experiments at UCLA to quantify linear and nonlinear mode conversion of lower hybrid to whistler waves.

  18. Whistler mode startup in the Michigan Mirror Machine

    International Nuclear Information System (INIS)

    Booske, J.; Getty, W.D.; Gilgenbach, R.M.; Goodman, T.; Whaley, D.; Olivieri, R.; Pitcher, E.; Simonetti, L.

    1985-01-01

    Results of investigations of whistler mode ECRH plasma startup in the Michigan Mirror Machine are presented. Electron-velocity-distribution and plasma-spatial-distribution time evolution are characterized by measurements from axially and radially moveable Langmuir probes, an endloss current detector, an electron cyclotron emission radiometer, a foil-filtered X-ray detector, and a diamagnetic loop at the mirror midplane. Measurements of the buildup of both electron density and perpendicular pressure (nkT/sub perpendicular/) are compared to predictions from various numerical models. Both modeling and data suggest the creation of a highly anisotropic electron velocity distribution function with a ''sloshing electron'' axial density profile

  19. Van Allen Probes observations of whistler-mode chorus with long-lived oscillating tones

    Science.gov (United States)

    Gao, Zhonglei; Su, Zhenpeng; Chen, Lunjin; Zheng, Huinan; Wang, Yuming; Wang, Shui

    2017-06-01

    Whistler-mode chorus plays an important role in the radiation belt electron dynamics. In the frequency-time spectrogram, chorus often appears as a hiss-like band and/or a series of short-lived (up to ˜1 s) discrete elements. Here we present some rarely reported chorus emissions with long-lived (up to 25 s) oscillating tones observed by the Van Allen Probes in the dayside (MLT ˜9-14) midlatitude (|MLAT|>15°) region. An oscillating tone can behave either regularly or irregularly and can even transform into a nearly constant tone (with a relatively narrow frequency sweep range). We suggest that these highly coherent oscillating tones were generated naturally rather than being related to some artificial VLF transmitters. Possible scenarios for the generation of the oscillating tone chorus are as follows: (1) being nonlinearly triggered by the accompanying hiss-like bands or (2) being caused by the modulation of the wave source. The details of the generation and evolution of such a long-lived oscillating tone chorus need to be investigated both theoretically and experimentally in the future.

  20. Lightninig Induced Sferics Correlated with Whistler Propagation

    Science.gov (United States)

    Compston, A. J.; Said, R.; Linscott, I.; Inan, U. S.; Parrot, M.

    2011-12-01

    Lightning discharges generate broadband electromagnetic pulses, known as sferics, that efficiently propagate through the Earth-ionosphere waveguide. Some sferic energy can escape the Earth-ionosphere waveguide and propagate in a whistler mode, enabled by Earth's magnetic field, through the ionosphere. In this presentation, we correlate lightning discharge location and time data from the National Lightning Detection Network (NLDN) in the United States with burst mode electric field measurements from the DEMETER spacecraft to quantify and model whistler propagation through the ionosphere. Using the International Reference Ionosphere (IRI) model for electron density and the International Geomagnetic Reference Field (IGRF) model for magnetic field, we compare measured propagation with the Full Wave Method (FWM) finite element numerical code developed by N. G. Lehtinen and U. S. Inan. While a few studies have analyzed whistler propagation through the ionosphere using spacecraft measurements, spacecraft data have yet to be compared with the FWM as we have done here.

  1. Self-focusing of whistler waves

    Science.gov (United States)

    Karpman, V. I.; Kaufman, R. N.; Shagalov, A. G.

    1992-01-01

    The theory of axially symmetric self-focusing of whistler waves, based on the full system of Maxwell equations, is developed. The plasma is described by the magnetohydrodynamic equations including the ponderomotive force from RF field. The nonlinear Schrodinger equations (NSE) for arbitrary azimuthal modes of whistler waves are derived. It is shown that they differ from the NSE for a scalar field; this is connected with an intrinsic angular momentum due to the rotating polarization of whistlers. It is shown that the self-focusing, as described by the NSE, differs in its final stage from the results following the full set of Maxwell equations. The latter gives defocusing after sufficient narrowing of the initial wave beam, due to transformation of the trapped wave into a nontrapped branch which is not contained in the NSE description. The oscillatory character of the defocusing is demonstrated.

  2. Whistler-mode waves in plasma

    International Nuclear Information System (INIS)

    Jolly, A.B.

    1968-05-01

    An apparatus designed to study the gyro-resonant interaction of whistler-mode radiation with fast electrons in a pulsed magneto-active gaseous afterglow plasma is described. Some results are presented of m = 0 and m = 1 bounded wave propagation studies with particular reference to their radial field structure and dispersion characteristics. A review of whistler-mode transmission experiments in laboratory and ionospheric plasma is given together with relevant theory. Whistler-mode propagation in naturally occurring 'ducts' of field-aligned ionization (analogous to trapped or bounded propagation) is also discussed. The theory of gyro-resonant interaction, including some computed results, is given in an appendix together with details of an electron source and detection systems. (author)

  3. Efficient trigger signal generation from wasted backward amplified stimulated emission at optical amplifiers for optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Kim Seung Taek

    2015-01-01

    Full Text Available This paper propose an optical structure to generate trigger signals for optical coherence tomography (OCT using backward light which is usually disposed. The backward light is called backward amplified stimulated emission generated from semiconductor optical amplifier (SOA when using swept wavelength tunable laser (SWTL. A circulator is applied to block undesirable lights in the SWTL instead of an isolator in common SWTL. The circulator also diverts backward amplified spontaneous lights, which finally bring out trigger signals for a high speed digitizer. The spectra of the forward lights at SOA and the waveform of the backward lights were measured to check the procedure of the trigger formation in the experiment. The results showed that the trigger signals from the proposed SWTL with the circulator was quite usable in OCT.

  4. Interaction of suprathermal solar wind electron fluxes with sheared whistler waves: fan instability

    Directory of Open Access Journals (Sweden)

    C. Krafft

    Full Text Available Several in situ measurements performed in the solar wind evidenced that solar type III radio bursts were some-times associated with locally excited Langmuir waves, high-energy electron fluxes and low-frequency electrostatic and electromagnetic waves; moreover, in some cases, the simultaneous identification of energetic electron fluxes, Langmuir and whistler waves was performed. This paper shows how whistlers can be excited in the disturbed solar wind through the so-called "fan instability" by interacting with energetic electrons at the anomalous Doppler resonance. This instability process, which is driven by the anisotropy in the energetic electron velocity distribution along the ambient magnetic field, does not require any positive slope in the suprathermal electron tail and thus can account for physical situations where plateaued reduced electron velocity distributions were observed in solar wind plasmas in association with Langmuir and whistler waves. Owing to linear calculations of growth rates, we show that for disturbed solar wind conditions (that is, when suprathermal particle fluxes propagate along the ambient magnetic field, the fan instability can excite VLF waves (whistlers and lower hybrid waves with characteristics close to those observed in space experiments.

    Key words. Space plasma physics (waves and instabilities – Radio Science (waves in plasma – Solar physics, astrophysics and astronomy (radio emissions

  5. Interaction of suprathermal solar wind electron fluxes with sheared whistler waves: fan instability

    Directory of Open Access Journals (Sweden)

    C. Krafft

    2003-07-01

    Full Text Available Several in situ measurements performed in the solar wind evidenced that solar type III radio bursts were some-times associated with locally excited Langmuir waves, high-energy electron fluxes and low-frequency electrostatic and electromagnetic waves; moreover, in some cases, the simultaneous identification of energetic electron fluxes, Langmuir and whistler waves was performed. This paper shows how whistlers can be excited in the disturbed solar wind through the so-called "fan instability" by interacting with energetic electrons at the anomalous Doppler resonance. This instability process, which is driven by the anisotropy in the energetic electron velocity distribution along the ambient magnetic field, does not require any positive slope in the suprathermal electron tail and thus can account for physical situations where plateaued reduced electron velocity distributions were observed in solar wind plasmas in association with Langmuir and whistler waves. Owing to linear calculations of growth rates, we show that for disturbed solar wind conditions (that is, when suprathermal particle fluxes propagate along the ambient magnetic field, the fan instability can excite VLF waves (whistlers and lower hybrid waves with characteristics close to those observed in space experiments.Key words. Space plasma physics (waves and instabilities – Radio Science (waves in plasma – Solar physics, astrophysics and astronomy (radio emissions

  6. Whistler instability in a magnetospheric duct

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, I.; Tripathi, V.K. (Indian Inst. of Tech., New Delhi (India). Dept. of Physics); Jain, V.K. (Jawaharlal Nehru Univ., New Delhi (India). School of Environmental Sciences)

    1989-04-01

    A whistler wave propagating through a preformed magnetospheric duct is susceptible to growth/amplification by an electron beam. The interaction is non-local and could be of Cerenkov or slow-cyclotron type. First-order perturbation theory is employed to obtain the growth rate for flat and Gaussian beam densities. (author).

  7. Heat Flux Inhibition by Whistlers: Experimental Confirmation

    International Nuclear Information System (INIS)

    Eichler, D.

    2002-01-01

    Heat flux in weakly magnetized collisionless plasma is, according to theoretical predictions, limited by whistler turbulence that is generated by heat flux instabilities near threshold. Observations of solar wind electrons by Gary and coworkers appear to confirm the limit on heat flux as being roughly the product of the magnetic energy density and the electron thermal velocity, in agreement with prediction (Pistinner and Eichler 1998)

  8. On the Origin of Whistler Mode Radiation in the Plasmasphere

    Science.gov (United States)

    Green, James L.; Boardsen, Scott; Garcia, Leonard; Taylor, W. W. L.; Fung, Shing F.; Reinisch, B. W.

    2004-01-01

    The origin of whistler mode radiation in the plasmasphere is examined from three years of plasma wave observations from the Dynamics Explorer and three years from the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft. These data are used to construct plasma wave intensity maps of whistler mode radiation in the plasmasphere. The highest average intensities of the radiation in the wave maps show source locations and/or sites of wave amplification. Each type of emission is classified based on its magnetic latitude and longitude rather than any spectral feature. Equatorial electromagnetic (EM) emissions (approx. 30-330 Hz), plasmaspheric hiss (approx. 330 Hz - 3.3 kHz), chorus (approx. 2 kHz - 6 kHz), and VLF transmitters (approx. 10-50 kHz) are the main types of waves that are clearly delineated in the plasma wave maps. Observations of the equatorial EM emissions show that the most intense region is on or near the magnetic equator in the afternoon sector and that during times of negative B(sub z) (interplanetary magnetic field),the maximum intensity moves from L values of 3 to less than 2. These observations are consistent with the origin of this emission being particle-wave interactions in or near the magnetic equator. Plasmaspheric hiss shows high intensity at high latitudes and low altitudes (L shells from 2 to 4) and in the magnetic equator over L values from 2 to 3 in the early afternoon sector. The longitudinal distribution of the hiss intensity (excluding the enhancement at the equator) is similar to the distribution of lightning: stronger over continents than over the ocean, stronger in the summer than winter, and stronger on the dayside than nightside. These observations strongly support lightning as the dominant source for plasmaspheric hiss, which through particle-wave interactions, maintains the slot region in the radiation belts. The enhancement of hiss at the magnetic equator is consistent with particle-wave interactions. The chorus

  9. Wave-Particle Interactions involving Whistler/Chorus Waves in the Earth's Radiation Belt

    Science.gov (United States)

    Echterling, N.; Schriver, D.; Roeder, J. L.; Fennell, J. F.

    2016-12-01

    Whistler mode chorus and electron cyclotron harmonic (ECH) waves are common in the Earth's radiation belt and have been detected by the Van Allen Probes at L 4-6 during the recovery of substorm plasma injections. During an event on January 13, 2013, quasi-periodic bursts of 16-40 keV electrons in very narrow, oblique ranges of pitch angles (75-80° and 100-105°) were observed by MagEIS, which were correlated with simultaneous bursts of upper-band, whistler-mode chorus waves. ECH emissions were also detected, but exhibited little correlation with the electron bursts. To understand the generation of these different wave emissions a linear theory and particle in cell (PIC) simulation study is being carried out using the observed velocity distribution functions as the starting point. Anisotropies and gradients in the distributions can lead to the generation of both whistler and ECH waves and the PIC simulations will be used to understand how these waves interact with the electrons non-linearly, which can lead to energy diffusion and pitch angle scattering. Comparisons between the simulation results and the Van Allen probe data will be made to determine acceleration, heating and transport of electrons in the radiation belt region due to wave-particle interactions.

  10. Inertial range spectrum of field-aligned whistler turbulence

    DEFF Research Database (Denmark)

    Dwivedi, Navin Kumar; Singh, Shobhana

    2017-01-01

    An analytical model to study the whistler turbulence spectrum and inertial range spectral scalings related with the electric and magnetic field spectra in a weakly non-collisional magnetized plasma is developed. In the present model, the dispersion relation of whistler wave propagating along...

  11. Hook whistlers observed at low latitude ground station Varanasi

    International Nuclear Information System (INIS)

    Khosa, P.N.; Lalmani; Ahmed, M.M.; Singh, B.D.

    1983-01-01

    Employing the Haselgrove ray tracing equations and a diffusive equilibrium model of the ionosphere, the propagation characteristics of hook whistlers recorded at low-latitude ground station Varanasi (geomag. lat., 16 0 6'N) are discussed. It is shown that the two traces of the hook whistlers are caused by the VLF waves radiated from the return stroke of a lightning discharge which after penetrating the ionosphere at two different entry points, propagated to the opposite hemisphere in the whistler mode and were received at 16 geomagnetic latitude. Further the crossing of ray paths for the same frequency leads to the explanation of the hook whistler. The lower and higher cut-off frequencies are explained in terms of their deviating away from the bunch of the recorded whistler waves and crossing of ray paths for the same frequency. (Auth.)

  12. Accelerated reduction in SO₂ emissions from the U.S. power sector triggered by changing prices of natural gas.

    Science.gov (United States)

    Lu, Xi; McElroy, Michael B; Wu, Gang; Nielsen, Chris P

    2012-07-17

    Emissions of sulfur dioxide (SO(2)) from the U.S. power sector decreased by 24% in 2009 relative to 2008. The Logarithmic Mean Divisia Index (LMDI) approach was applied to isolate the factors responsible for this decrease. It is concluded that 15% of the decrease can be attributed to the drop in demand for electricity triggered by the economic recession, and 28% can be attributed to switching of fuel from coal to gas responding to the decrease in prices for the latter. The largest factor in the decrease, close to 57%, resulted from an overall decline in emissions per unit of power generated from coal. This is attributed in part to selective idling of older, less efficient coal plants that generally do not incorporate technology for sulfur removal, and in part to continued investments by the power sector in removal equipment in response to the requirements limiting emissions imposed by the U.S. Environmental Protection Agency (U.S. EPA). The paper argues further that imposition of a modest tax on emissions of carbon would have ancillary benefits in terms of emissions of SO(2).

  13. On whistler-mode group velocity

    International Nuclear Information System (INIS)

    Sazhin, S.S.

    1986-01-01

    An analytical of the group velocity of whistler-mode waves propagating parallel to the magnetic field in a hot anisotropic plasma is presented. Some simple approximate formulae, which can be used for the magnetospheric applications, are derived. These formulae can predict some properties of this group velocity which were not previously recognized or were obtained by numerical methods. In particular, it is pointed out that the anisotropy tends to compensate for the influence of the electron temperature on the value of the group velocity when the wave frequency is well below the electron gyrofrequency. It is predicted, that under conditions at frequencies near the electron gyrofrequency, this velocity tends towards zero

  14. Slinky-whistler dispersion relation from ``scaling''

    Science.gov (United States)

    Crawford, Frank S.

    1990-10-01

    Slinkies come in two sizes, ``regular'' and ``junior.'' Using 61% of the total length of the regular slinky, a whistler is obtained that sounds to the ear exactly like that obtained using the total length of the junior. That agrees with the proposed (approximate) dispersion relation ω=ck2r. If n is taken to be unknown in an assumed dispersion relation ω=ck(kr)n, then, by ear, with no equipment, it is found out n=0.83±0.17, in reasonable agreement with the proposed n=1.0.

  15. DEMETER observations of subprotonospheric whistlers and their analysis

    Science.gov (United States)

    Chum, J.; Santolik, O.; Parrot, M.

    2009-04-01

    We report observations of an interesting class of whistlers trapped in the ionosphere, so called SubProtonospheric (SP) whistlers. The SP whistler consists of a series of low dispersion echoes that result from repeated reflections between the base of the ionosphere and the altitudes up to ~1000 km. We use wave normal angles and plasma characteristics measured by the DEMETER microsatellite as an input for a three dimensional ray tracing technique. For several SP whistlers we have also succeeded in finding the causative lightning. We show that the reflections and formation of the SP whistlers takes place owing to an oblique propagation, with respect to the magnetic field, in the wave guide formed by a profile of the increasing LHR frequency in the upper ionosphere and the base of the ionosphere. We have observed propagation across the magnetic meridian planes. We conclude that the individual components of the SP whistler propagate along different ray paths. The reflected components enter the ionosphere at relatively large distances from the satellite foot print and experience a spread of wave normal angles during this entry. Depending on the initial wave normal angle, these waves undergo a different number of reflections before reaching the satellite, thus arriving with different time delays. However, the first component observed of a SP whistler is formed by waves entering the ionosphere at relatively small distances from the satellite foot print and propagating at relatively small wave normal angles. These waves do not reflect above the satellite, but propagate to the opposite hemisphere.

  16. Competing processes of whistler and electrostatic instabilities in the magnetosphere

    International Nuclear Information System (INIS)

    Omura, Y.; Matsumoto, H.

    1987-01-01

    Competing processes of whistler mode and electrostatic mode instabilities induced by an electron beam are studied by a linear growth rate analysis and by an electromagnetic particle simulation. In addition to a background cold plasma we assumed an electron beam drifting along a static magnetic field. We studied excitation of whistler and electrostatic mode waves in the direction of the static magnetic field. We first calculated linear growth rates for the whistler mode and electrostatic mode instabilities, assuming various possible parameters in the equatorial magnetosphere. We found that the growth rate for the electrostatic instability is always larger than that of the whistler mode instability. A short simulation run with a monoenergetic electron beam demonstrates that a monoenergetic beam can hardly give energy to whistler mode waves as a result of competition with faster growing electrostatic waves, because the beam electrons are trapped and diffused by the electrostatic waves, and hence the growth rates for whistler mode waves become very small. A long simulation run starting with a warm electron beam demonstrates that whistler mode waves are excited in spite of the small growth rates and the coexisting quasi-linear electrostatic diffusion process

  17. Study of Oblique Propagating Whistler Mode Waves in Presence of Parallel DC Electric Field in Magnetosphere of Saturn

    Directory of Open Access Journals (Sweden)

    R. Kaur

    2017-03-01

    Full Text Available In this paper whistler mode waves have been investigated in magnetosphere of Saturn. The derivation for perturbed distribution function, dispersion relation and growth rate have been determined by using the method of characteristic and kinetic approach. Analytical expressions for growth rate and real frequency of whistlers propagating oblique to magnetic field direction are attained. Calculations have been performed at 6 radial distances in plasma sheet region of Saturn’s magnetosphere as per data provided by Cassini. Work has been extended for bi-Maxwellian as well as Loss-cone distribution function. Parametric analysis show that temperature anisotropy, increase in number density, energy density and angle of propagation increases the growth rate of whistler waves along with significant shift in wave number. In case of Loss-cone distribution, increase in growth rate of whistlers is significantly more than for bi-Maxwellian distribution function. Generation of second harmonics can also be seen in the graphs plotted. It is concluded that parallel DC field stabilizes the wave and temperature anisotropy, angle of propagation, number density and energy density of electrons enhances the growth rate. Thus the results are of importance in analyzing observed VLF emissions over wide spectrum of frequency range in Saturnian magnetosphere. The analytical model developed can also be used to study various types of instabilities in planetary magnetospheres.

  18. Interactions between microbial-feeding and predatory soil fauna trigger N2O emissions

    NARCIS (Netherlands)

    Thakur, M.P.; Groenigen, van J.W.; Kuiper, I.; Deyn, de G.B.

    2014-01-01

    Recent research has shown that microbial-feeding invertebrate soil fauna species can significantly contribute to N2O emissions. However, in soil food webs microbial-feeding soil fauna interact with each other and with their predators, which affects microbial activity. To date we lack empirical tests

  19. Propagation of magnetosonic and whistler-mode waves from the magnetosphere and atmosphere into the ionosphere

    Science.gov (United States)

    Santolik, O.; Parrot, M.; Chum, J.; Nemec, F.

    2009-04-01

    We summarize observations of the DEMETER spacecraft in the top-side ionosphere related to the lightning activity, to the downward propagating magnetospheric chorus emissions and to the magnetosonic harmonic ELF emissions close to the geomagnetic equator. At the 707 km altitude of DEMETER, we have observed 3D electric and magnetic field waveforms of fractional-hop whistlers. We identify corresponding source lightning strokes and we perform multidimensional analysis of the measurements and obtain detailed information on wave polarization characteristics and propagation directions. This allows us for the first time to combine these measurements with ray tracing simulation in order to directly characterize how the radiation penetrates through the ionosphere. We also interpret observations of low-altitude electromagnetic ELF hiss observed on the dayside at subauroral latitudes. These waves propagate with downward directed wave vectors which are slightly equatorward inclined at lower magnetic latitudes and slightly poleward inclined at higher latitudes. Reverse ray tracing indicates a possible source region near the geomagnetic equator at a radial distance between 5 and 7 Earth radii and we find that low-altitude ELF hiss contains discrete time-frequency structures resembling wave packets of whistler mode chorus. The reverse raypaths of ELF hiss are consistent with the hypothesis that the frequently observed dayside ELF hiss is a low-altitude manifestation of natural magnetospheric emissions of whistler mode chorus. Finally, we analyze waves that propagate in the extraordinary magnetosonic mode to the ionosphere from larger radial distances close to the plane of the geomagnetic equator. These waves show a characteristic harmonic structure very similar to previously reported observations of equatorial noise in the magnetosphere. The observed mode structure is influenced by the presence of multiple ions in the plasma of the top-side ionosphere but the spectral and

  20. Wave-Particle Interactions Involving Correlated Electron Bursts and Whistler Chorus in Earth's Radiation Belts

    Science.gov (United States)

    Echterling, N.; Schriver, D.; Roeder, J. L.; Fennell, J. F.

    2017-12-01

    During the recovery phase of substorm plasma injections, the Van Allen Probes commonly observe events of quasi-periodic energetic electron bursts correlating with simultaneously detected upper-band, whistler-mode chorus emissions. These electron bursts exhibit narrow ranges of pitch angles (75-80° and 100-105°) and energies (20-40 keV). Electron cyclotron harmonic (ECH) emissions are also commonly detected, but typically do not display correlation with the electron bursts. To examine sources of free energy and the generation of these wave emissions, an observed electron velocity distribution on January 13, 2013 is used as the starting condition for a particle in cell (PIC) simulation. Effects of temperature anisotropy (perpendicular temperature greater than parallel temperature), the presence of a loss cone and a cold electron population on the generation of whistler and ECH waves are examined to understand wave generation and nonlinear interactions with the particle population. These nonlinear interactions produce energy diffusion along with strong pitch angle scattering into the loss cone on the order of milliseconds, which is faster than a typical bounce period of seconds. To examine the quasi-periodic nature of the electron bursts, a loss-cone recycling technique is implemented to model the effects of the periodic emptying of the loss cone and electron injection on the growth of whistler and ECH waves. The results of the simulations are compared to the Van Allen Probe observations to determine electron acceleration, heating and transport in Earth's radiation belts due to wave-particle interactions.

  1. Wavenumber spectrum of whistler turbulence: Particle-in-cell simulation

    International Nuclear Information System (INIS)

    Saito, S.; Gary, S. Peter; Narita, Y.

    2010-01-01

    The forward cascade of decaying whistler turbulence is studied in low beta plasma to understand essential properties of the energy spectrum at electron scales, by using a two-dimensional electromagnetic particle-in-cell (PIC) simulation. This simulation demonstrates turbulence in which the energy cascade rate is greater than the dissipation rate at the electron inertial length. The PIC simulation shows that the magnetic energy spectrum of forward-cascaded whistler turbulence at electron inertial scales is anisotropic and develops a very steep power-law spectrum which is consistent with recent solar wind observations. A comparison of the simulated spectrum with that predicted by a phenomenological turbulence scaling model suggests that the energy cascade at the electron inertial scale depends on both magnetic fluctuations and electron velocity fluctuations, as well as on the whistler dispersion relation. Thus, not only kinetic Alfven turbulence but also whistler turbulence may explain recent solar wind observations of very steep magnetic spectra at short scales.

  2. Dispersion properties of ducted whistlers, generated by lightning discharge

    Directory of Open Access Journals (Sweden)

    D. L. Pasmanik

    2005-06-01

    Full Text Available Whistler-mode wave propagation in magnetospheric ducts of enhanced cold plasma density is studied. The case of the arbitrary ratio of the duct radius to the whistler wavelength is considered, where the ray-tracing method is not applicable. The set of duct eigenmodes and their spatial structure are analysed and dependencies of eigenmode propagation properties on the duct characteristics are studied. Special attention is paid to the analysis of the group delay time of one-hop propagation of the whistler wave packet along the duct. We found that, in contrast to the case of a wide duct, the group delay time in a rather narrow duct decreases as the eigenmode number increases. The results obtained are suggested for an explanation of some types of multi-component whistler signals.

  3. Whistler dominated quasi-collisionless magnetic reconnection

    International Nuclear Information System (INIS)

    Biskamp, D.; Drake, J.F.

    1995-05-01

    A theory of fast quasi-collisionless reconnection is presented. For spatial scales smaller than the ion inertia length the electrons decouple from the ions and the dynamics is described by electron magnetohydrodynamics (EMHD). A qualitative analysis of the reconnection region is obtained, which is corroborated by numerical simulations. The main results are that in contrast to resistive reconnection no macroscopic current sheet is generated, and the reconnection rate is independent of the smallness parameters of the system, i.e. the electron inertia length and the dissipation coefficients. At larger scales the coupling to the ions is important, which, however, does not change the small-scale dynamics. The reconnection rate is only limited by ion inertia being independent of the electron inertia scale and the dissipation coefficients. Reconnection is much faster than in the absence of the whistler mode. (orig.)

  4. Analytic properties of the whistler dispersion function

    International Nuclear Information System (INIS)

    Daniell, G.J.

    1986-01-01

    The analytic properties of the dispersion function of a whistler are investigated in the complex frequency plane. It possesses a pole and a branch point at a frequency equal to the minimum value of the electron gyrofrequency along the path of propagation. An integral equation relates the dispersion function to the distribution of magnetospheric electrons along the path and the solution of this equation is obtained. It is found that the electron density in the equatorial plane is very simply related to the dispersion function. A discussion of approximate formulae to represent the dispersion shows how particular terms can be related to attributes of the electron density distribution, and a new approximate formula is proposed. (author)

  5. Decay instability of a whistler in a plasma

    International Nuclear Information System (INIS)

    Tewari, D.P.; Sharma, R.R.

    1982-01-01

    The parametric instabilities of a high power whistler in a high density plasma possess large growth rate when the scattered sideband is an electrostatic lower hybrid mode. The efficient channels of decay include oscillating two stream instability, nonlinear Landau damping and resonant decay involving ion acoustic and ion cyclotron modes. The processes of nonlinear scattering, i.e., the ones possessing whistler sidebands are relatively less significant. (author)

  6. Initial Search for Triggered Gamma Emission from 178Hfm2 Using the YSU Miniball Array

    International Nuclear Information System (INIS)

    Carroll, J. J.; Burnett, J.; Drummond, T.; Lepak, J.; Propri, R.; Smith, D.; Karamian, S. A.; Adam, J.; Stedile, F.; Agee, F. J.

    2002-01-01

    Experiments with the long-lived, high-K isomer 178 Hf m2 have been recognized as intriguing tests of multi-quasiparticle state structures and their interactions with external radiation. A triggered release of the energy stored by this isomer, 2.5 MeV per nucleus or 1.2 GJ/gram, in the form of a gamma-ray burst might prove valuable for numerous applications. The observation of 'accelerated' decay of 178 Hf m2 during irradiation by 90-keV bremsstrahlung has already been reported, but with poor statistical accuracy due to the experimental approach. That approach employed single Ge detectors to seek increases in the areas of peaks at energies corresponding to transitions in the spontaneous decay of the isomer. The need for better quality data to confirm those results has motivated the development of improved detection concepts. One such concept was utilized here to perform an initial search for low-energy ( 178 Hf m2 using the YSU miniball detector array.

  7. On the relationship between whistlers, chorus, hiss, saucers, broadband electrostatic noise and the resonance cone

    International Nuclear Information System (INIS)

    Andre, M.

    1985-06-01

    Waves named whistlers, chorus, hiss, saucers and low hybrid waves are often detected in space plasmas. These emissions are observed between the lower hybrid frequency and the electron gyrofrequency, but are given different names due to properties such as coherence, time duration and polarization. The waves are often classified as either electrostatic or electromagnetic, and are somtimes said to propagate on the resonance cone of the whistler mode. With the aid of dispersion surfaces, plots of frequency versus wavevector components, it can be shown that all these waves often correspond to one wave mode (one single surface). Sometimes the emissions called broadband electrostatic noise also propagate in this mode. Since electromagnetic theory for all angles of propagation relative to the ambient magnetic field is used, the smooth transition between so called eletrostatic and so called electromagnetic waves can be described in terms of a gradual change of the wavevector. To give an example of an instability over a wide range of wavevectors, a beam of auroral (keV) electrons is introduced. The highest temporal and spatial growth rates rates caused by such a beam can occur at the plasma frequency. However, a dispersion surface may be used to give some simple arguments showing that in an inhomogeneous plasma, the strongest emissions may occur below the plasma frequency. Furthermore, the significance of the resonance cone is discussed. (Author)

  8. Mid-Mountain Clouds at Whistler During the Vancouver 2010 Winter Olympics and Paralympics

    Science.gov (United States)

    Mo, Ruping; Joe, Paul; Isaac, George A.; Gultepe, Ismail; Rasmussen, Roy; Milbrandt, Jason; McTaggart-Cowan, Ron; Mailhot, Jocelyn; Brugman, Melinda; Smith, Trevor; Scott, Bill

    2014-01-01

    A comprehensive study of mid-mountain clouds and their impacts on the Vancouver 2010 Winter Olympics and Paralympics is presented. Mid-mountain clouds were frequently present on the Whistler alpine venue, as identified in an extensive archive of webcam images over a 45-day period from February 5 to March 21, 2010. These clouds posed serious forecast challenges and had significant impacts on some Olympic and Paralympic alpine skiing competitions. Under fair weather conditions, a diurnal upslope (anabatic) flow can work in concert with a diurnal temperature inversion aloft to produce a localized phenomenon known as "Harvey's Cloud" at Whistler. Two detailed case studies in this paper suggest that mid-mountain clouds can also develop in the area as a result of a moist valley flow interacting with a downslope flow descending from the mountaintop. A southerly inflow through the Sea-to-Sky corridor can be channeled by the local topography into a westerly upslope flow toward Whistler Mountain, resulting in orographic clouds on the alpine venue. Under favorable circumstances, these clouds are trapped to the mid-mountain zone by the leeward subsidence of an elevated southerly flow. The presence of the downslope subsidence was manifested by a distinguished dry layer observed on the top of the mid-mountain clouds in both cases. It is the subsidence-induced adiabatic warming that imposes a strong buoyant suppression to trap the mid-mountain cloud. On the other hand, the subsidence-induced dry layer has the potential to trigger evaporative instability to periodically breakup the mid-mountain cloud.

  9. Nonlinear Whistler Wave Physics in the Radiation Belts

    Science.gov (United States)

    Crabtree, Chris

    2016-10-01

    Wave particle interactions between electrons and whistler waves are a dominant mechanism for controlling the dynamics of energetic electrons in the radiation belts. They are responsible for loss, via pitch-angle scattering of electrons into the loss cone, and energization to millions of electron volts. It has previously been theorized that large amplitude waves on the whistler branch may scatter their wave-vector nonlinearly via nonlinear Landau damping leading to important consequences for the global distribution of whistler wave energy density and hence the energetic electrons. It can dramatically reduce the lifetime of energetic electrons in the radiation belts by increasing the pitch angle scattering rate. The fundamental building block of this theory has now been confirmed through laboratory experiments. Here we report on in situ observations of wave electro-magnetic fields from the EMFISIS instrument on board NASA's Van Allen Probes that show the signatures of nonlinear scattering of whistler waves in the inner radiation belts. In the outer radiation belts, whistler mode chorus is believed to be responsible for the energization of electrons from 10s of Kev to MeV energies. Chorus is characterized by bursty large amplitude whistler mode waves with frequencies that change as a function of time on timescales corresponding to their growth. Theories explaining the chirping have been developed for decades based on electron trapping dynamics in a coherent wave. New high time resolution wave data from the Van Allen probes and advanced spectral techniques are revealing that the wave dynamics is highly structured, with sub-elements consisting of multiple chirping waves with discrete frequency hops between sub-elements. Laboratory experiments with energetic electron beams are currently reproducing the complex frequency vs time dynamics of whistler waves and in addition revealing signatures of wave-wave and beat-wave nonlinear wave-particle interactions. These new data

  10. Hot times in Whistler : energy saving hybrid systems in area hotels

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2008-01-15

    The resort of Whistler in British Columbia is to host the 2010 Winter Olympics, and the town of Whistler has committed to reducing energy consumption and emissions output in the community's 9500 dwelling units. Commercial hotels and mountain operations in the region are facing higher costs associated with tanked propane supply systems and higher infrastructure costs for some of the proposed alternatives. This article described a hybrid heating system designed by Sempa Power Systems. The systems have now been installed in conference centres and on all large mountain lodge complexes in the region. The hybrid heating system is a patent-pending system that automatically load-balances fossil fuel sources with electricity consumption to reduce energy costs, decrease GHG emissions, and increase efficiencies. Clients at the complexes are monitored online in real time and analyses of empirical data are compared with actual consumption to historical baseline averages. It was concluded that complexes in which the systems have been installed are averaging 28 per cent energy savings, a 39 per cent reduction in greenhouse gases (GHGs), and a 13 per cent reduction in energy consumption. 2 figs.

  11. Propagation of whistler mode chorus to low altitudes: Spacecraft observations of structured ELF hiss

    Science.gov (United States)

    SantolíK, O.; Chum, J.; Parrot, M.; Gurnett, D. A.; Pickett, J. S.; Cornilleau-Wehrlin, N.

    2006-10-01

    We interpret observations of low-altitude electromagnetic ELF hiss observed on the dayside at subauroral latitudes. A divergent propagation pattern has been reported between 50° and 75° of geomagnetic latitude. The waves propagate with downward directed wave vectors which are slightly equatorward inclined at lower magnetic latitudes and slightly poleward inclined at higher latitudes. Reverse ray tracing using different plasma density models indicates a possible source region near the geomagnetic equator at a radial distance between 5 and 7 Earth radii by a mechanism acting on highly oblique wave vectors near the local Gendrin angle. We analyze waveforms received at altitudes of 700-1200 km by the Freja and DEMETER spacecraft and we find that low-altitude ELF hiss contains discrete time-frequency structures resembling wave packets of whistler mode chorus. Emissions of chorus also predominantly occur on the dawnside and dayside and have recently been considered as a possible source of highly accelerated electrons in the outer Van Allen radiation belt. Detailed measurements of the Cluster spacecraft at radial distances of 4-5 Earth radii show chorus propagating downward from the source region localized close to the equator. The time-frequency structure and frequencies of chorus observed by Cluster along the reverse raypaths of ELF hiss are consistent with the hypothesis that the frequently observed dayside ELF hiss is just the low-altitude manifestation of natural magnetospheric emissions of whistler mode chorus.

  12. Analysis of subprotonospheric whistlers observed by DEMETER: A case study

    Science.gov (United States)

    Chum, Jaroslav; Santolik, Ondrej; Parrot, Michel

    2009-02-01

    Subprotonospheric (SP) whistlers consist of a series of low-dispersion components that result from repeated reflections between the base of the ionosphere and altitudes up to ~1000 km. We have used wave-normal angles and plasma characteristics measured by the DEMETER microsatellite as an input for a three-dimensional ray tracing technique. For several SP whistlers we have also succeeded in finding the causative lightning located at relatively large distances from the satellite footprint along the geomagnetic field line. We show that the reflections and formation of the SP whistlers take place owing to an oblique propagation, with respect to the magnetic field, in the waveguide formed by a profile of the increasing lower hybrid resonance frequency in the upper ionosphere and the base of the ionosphere. We have observed propagation across the magnetic meridian planes. We conclude that the individual components of the SP whistler propagate along different raypaths. The reflected components enter the ionosphere at relatively large distances from the satellite footprint and experience a spread of wave-normal angles during this entry. Depending on the initial wave-normal angle, these waves undergo a different number of reflections before reaching the satellite, thus arriving with different time delays. However, the first component observed of a SP whistler is formed by waves entering the ionosphere at relatively small distances from the satellite footprint and at relatively small wave-normal angles. These waves do not reflect above the satellite but propagate to the opposite hemisphere.

  13. Dislocation Enhancement of Seismic-Frequency Attenuation: Subgrain Boundary Diffusion and Triggered, Critical Emission of Dislocations

    Science.gov (United States)

    Cooper, R. F.; McCarthy, C.

    2012-12-01

    Combined compressional creep and (Young's-modulus) attenuation experiments on polycrystalline ice-I (200 ≤ T[K] ≤ 260; 3 ≤ d[μm] ≤ 500; σmean = 1MPa and Δσ = 0.16MPa applied in a frequency range 10-4 ≤ ν[Hz] ≤ 10-1) demonstrate the attenuation behavior associated with the seismic attenuation band and the "high-temperature background," i.e., a power-law response Q-1 ∝ ν-m with m ~ 0.33. This response has, in general, been associated with grain boundary sliding rate-limited by atomic diffusion [e.g., 1-3], a mechanism that is very sensitive to grain size. In our experiments, however, with a grain size variation ~102, the attenuation response is independent of grain size, to first order. Scrutiny of the physics suggests that the attenuation is effected primarily by diffusive relaxation of subgrain boundaries [4, 5], the size of which, in materials deforming by a dislocation mechanism (as is the ice in our experiments), is set by the deviatoric stress [6, 7]. Applying the diffusion-effected physics to the subgrain size matches the universal scaling [e.g., 3] for materials that are linear-viscoelastic. Our ice specimens, however, demonstrate modest non-linearity, resulting in greater attenuation than that associated with the diffusion process [cf. 8] and yet retain the power-law form for attenuation, including the same slope m. The result is consistent with "self-organized critical" behavior in dislocation emission [9, 10] and the physics overall can be understood via models of self-similar scaling of crystalline (effective) viscosity [e.g., 11]. The potential application to seismic studies is profound: for example, if the upper mantle of Earth is convecting via a dislocation-creep or dislocation-accommodated grain-boundary-sliding mechanism, then the attenuation response is related not to the grain size, but rather to the subgrain structure associated with the creep of the rock. Thus, seismic attenuation measurements may well be useful for

  14. Redox-Triggered Bonding-Induced Emission of Thiol-Functionalized Gold Nanoclusters for Luminescence Turn-On Detection of Molecular Oxygen.

    Science.gov (United States)

    Ao, Hang; Feng, Hui; Zhao, Mengting; Zhao, Meizhi; Chen, Jianrong; Qian, Zhaosheng

    2017-11-22

    Most optical sensors for molecular oxygen were developed based on the quenching effect of the luminescence of oxygen-sensitive probes; however, the signal turn-off mode of these probes is undesirable to quantify and visualize molecular oxygen. Herein, we report a novel luminescence turn-on detection strategy for molecular oxygen via the specific oxygen-triggered bonding-induced emission of thiol-functionalized gold nanoclusters. Thiol-functionalized gold nanoclusters were prepared by a facile one-step synthesis, and as-prepared gold nanoclusters possess significant aggregation-induced emission (AIE) property. It is the first time to discover the oxygen-triggered bonding-induced emission (BIE) behavior of gold nanoclusters, which results in disulfide-linked covalent bonding assemblies with intensely red luminescence. This specific redox-triggered BIE is capable of quantitatively detecting dissolved oxygen in aqueous solution in a light-up manner, and trace amount of dissolved oxygen at ppb level is achieved based on this detection method. A facile and convenient test strip for oxygen detection was also developed to monitor molecular oxygen in a gas matrix. Covalent bonding-induced emission is proven to be a more efficient way to attain high brightness of AIEgens than a physical aggregation-induced emission process, and provides a more convenient and desirable detection method for molecular oxygen than the previous sensors.

  15. The characteristic response of whistler mode waves to interplanetary shocks

    Science.gov (United States)

    Yue, C.; Chen, L.; Bortnik, J.; Ma, Q.; Thorne, R. M.; Angelopoulos, V.; Li, J.; An, X.; Zhou, C.

    2017-12-01

    Magnetospheric whistler mode waves play a key role in regulating the dynamics of the electron radiation belts. Recent satellite observations indicate a significant influence of interplanetary (IP) shocks on whistler mode wave power in the inner magnetosphere. In this study, we statistically investigate the response of whistler mode chorus and plasmaspheric hiss to IP shocks based on Van Allen Probes and THEMIS satellite observations. Immediately after the IP shock arrival, chorus wave power is usually intensified, often at dawn, while plasmaspheric hiss wave power predominantly decreases near the dayside but intensifies near the nightside. We conclude that chorus wave intensification outside the plasmasphere is probably associated with the suprathermal electron flux enhancement caused by the IP shock. On the other hand, the solar wind dynamic pressure increase changes the magnetic field configuration to favor ray penetration into the nightside and promote ray refraction away from the dayside, explaining the magnetic local time (MLT) dependent responses of plasmaspheric hiss waves following IP shock arrivals.

  16. Modeling whistler wave generation regimes in magnetospheric cyclotron maser

    Directory of Open Access Journals (Sweden)

    D. L. Pasmanik

    2004-11-01

    Full Text Available Numerical analysis of the model for cyclotron instability in the Earth's magnetosphere is performed. This model, based on the self-consistent set of equations of quasi-linear plasma theory, describes different regimes of wave generation and related energetic particle precipitation. As the source of free energy the injection of energetic electrons with transverse anisotropic distribution function to the interaction region is considered. A parametric study of the model is performed. The main attention is paid to the analysis of generation regimes for different characteristics of energetic electron source, such as the shape of pitch angle distributions and its intensity. Two mechanisms of removal of energetic electrons from a generation region are considered, one is due to the particle precipitation through the loss cone and another one is related to the magnetic drift of energetic particles. It was confirmed that two main regimes occur in this system in the presence of a constant particle source, in the case of precipitation losses. At small source intensity relaxation oscillations were found, whose parameters are in good agreement with simplified analytical theory developed earlier. At a larger source intensity, transition to a periodic generation occurs. In the case of drift losses the regime of self-sustained periodic generation regime is realized for source intensity higher than some threshold. The dependencies of repetition period and dynamic spectrum shape on the source parameters were studied in detail. In addition to simple periodic regimes, those with more complex spectral forms were found. In particular, alteration of spikes with different spectral shape can take place. It was also shown that quasi-stationary generation at the low-frequency band can coexist with periodic modulation at higher frequencies. On the basis of the results obtained, the model for explanation of quasi-periodic whistler wave emissions is verified.

  17. Modeling whistler wave generation regimes in magnetospheric cyclotron maser

    Directory of Open Access Journals (Sweden)

    D. L. Pasmanik

    2004-11-01

    quasi-periodic whistler wave emissions is verified.

  18. Los seis proyectos de james Abbott Mcneill Whistler

    OpenAIRE

    Radyk, Lucrecia

    2017-01-01

    Una serie de bocetos al óleo de James McNeill Whistler presenta un caso particular en la obra de este pintor, reconocido como uno de los iniciadores de la estética del ?arte por el arte? en Inglaterra. Se propone un recorrido por textos contemporáneos de las obras, en los que se alude a los Seis proyectos, a fin de ubicarlos en el contexto de la obra de Whistler y en relación con sus postulados estéticos. Nos interesa demostrar en especial el carácter central de estas pinturas en la obra ...

  19. Roles of whistler mode waves and magnetosonic waves in changing the outer radiation belt and the slot region

    Science.gov (United States)

    Li, L. Y.; Yu, J.; Cao, J. B.; Yang, J. Y.; Li, X.; Baker, D. N.; Reeves, G. D.; Spence, H.

    2017-05-01

    Using the Van Allen Probe long-term (2013-2015) observations and quasi-linear simulations of wave-particle interactions, we examine the combined or competing effects of whistler mode waves (chorus or hiss) and magnetosonic (MS) waves on energetic (0.5 MeV) electrons inside and outside the plasmasphere. Although whistler mode chorus waves and MS waves can singly or jointly accelerate electrons from the hundreds of keV energy to the MeV energy in the low-density trough, most of the relativistic electron enhancement events are best correlated with the chorus wave emissions outside the plasmapause. Inside the plasmasphere, intense plasmaspheric hiss can cause the net loss of relativistic electrons via persistent pitch angle scattering, regardless of whether MS waves were present or not. The intense hiss waves not only create the energy-dependent electron slot region but also remove a lot of the outer radiation belt electrons when the expanding dayside plasmasphere frequently covers the outer zone. Since whistler mode waves (chorus or hiss) can resonate with more electrons than MS waves, they play dominant roles in changing the outer radiation belt and the slot region. However, MS waves can accelerate the energetic electrons below 400 keV and weaken their loss inside the plasmapause. Thus, MS waves and plasmaspheric hiss generate different competing effects on energetic and relativistic electrons in the high-density plasmasphere.

  20. Empirical modeling of whistler-mode chorus and hiss in the inner magnetosphere using measurements of the Van Allen Probes

    Science.gov (United States)

    Santolik, Ondrej; Hospodarsky, George B.; Kurth, William S.; Kletzing, Craig A.

    2017-04-01

    Recent studies of the dynamics of energetic in the Earth radiation belts show that whistler mode chorus and hiss play an important role. This especially concerns the slot region and the outer Van Allen radiation belts where empirical wave models are used as a component of existing approaches. We analyze these whistler-mode waves using a database of survey measurements of the Waves instruments of the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) onboard the Van Allen Probes. We use multicomponent data to estimate wave polarization and propagation parameters and to asses variability of wave amplitudes as a function of position and geomagnetic activity. Four years of Van Allen Probes EMFISIS Waves survey data give a good orbital coverage in L, latitude, and MLT. Average amplitudes increase with geomagnetic activity but the observed amplitude variations are still much larger than this effect. Statistics of planarity and wave vector directions are strongly linked to wave amplitudes. The planarity of magnetic field polarization is high for strong chorus and its wave normal directions are well defined. We obtain low planarities of the magnetic field polarization for a substantial fraction of plasmaspheric hiss. This invalidates the assumption of a single plane wave for these whistler mode emissions.

  1. Generation of nonlinear electric field bursts in the outer radiation belt through the parametric decay of whistler waves

    OpenAIRE

    Agapitov, O. V.; Krasnoselskikh, V; Mozer, F. S.; Artemyev, A.V.; Volokitin, A.S.

    2015-01-01

    International audience; Huge numbers of different nonlinear structures (double layers, electron holes, nonlinear whistlers, etc., referred to as Time Domain Structures, TDS) have been observed by the electric field experiment on the Van Allen Probes. Some of them are associated with whistler waves. Such TDS often emerge on the forward edges of the whistler wave packets and form chains. The parametric decay of a whistler wave into a whistler wave propagating in the opposite direction and an el...

  2. Observations of unusual whistlers during daytime at Jammu

    Indian Academy of Sciences (India)

    After leakage from the duct, the waves might have propagated in the earth- ionosphere ... of wave electric field. The antenna is rendered aperiodic with the help of a suitable RC net- work, to avoid any possible ringing effect (Singh et al 2004b). The whistler ... radio noise is intense in the whole frequency band, but it is not ...

  3. Observations of unusual whistlers during daytime at Jammu

    Indian Academy of Sciences (India)

    They are interpreted as one-hop ducted whistlers having propagated along higher -values in closely spaced narrow ducts from the opposite hemispheres. After leakage from the duct, the waves might have propagated in the earthionosphere waveguide towards the equator in surface mode.Tentative explanation of the ...

  4. Properties of Whistler Waves in Warm Electron Plasmas

    Science.gov (United States)

    Zhao, Jinsong

    2017-11-01

    Dispersion relation and electromagnetic properties of obliquely propagating whistler waves are investigated on the basis of a warm electron fluid model. The magnetic field of whistler waves is nearly circularly polarized with respect to the wave vector in a plasma where the electron plasma frequency {{{Ω }}}{pe} is much larger than the electron cyclotron frequency {{{Ω }}}{ce}, and the magnetic field polarization can become elliptical, or even linear, polarization as {{{Ω }}}{pe}≲ {{{Ω }}}{ce}. In the plasmas with {{{Ω }}}{pe}fluid model. Near the resonant frequency, the whistler wave approximates a quasi-magnetostatic mode, not a quasi-electrostatic mode in the cold electron plasmas. Moreover, the detailed mode properties are given in Earth’s magnetosphere, the solar active region, and Jupiter’s polar cap. Furthermore, the study proposes that the ratio of the electrostatic to electromagnetic component of the electric field can be used to distinguish the whistler mode from the Z-mode in the frequency range of {{{Ω }}}{pe}< ω < {{{Ω }}}{ce} in the solar active region and Jupiter’s polar cap.

  5. James Abbot McNeill Whistler: "At the Piano."

    Science.gov (United States)

    Hallenberg, Heather

    1987-01-01

    "At the Piano," an oil-on-canvas painting completed in 1859 by James Abbot McNeill Whistler, is used as the basis of a lesson designed to help junior high school students analyze the painting's mood, subject matter, and composition. (JDH)

  6. Propagation Spectrograms of Whistler-Mode Radiation from Lightning

    Czech Academy of Sciences Publication Activity Database

    Santolík, Ondřej; Parrot, M.; Chum, Jaroslav

    2008-01-01

    Roč. 36, č. 4 (2008), s. 1166-1167 ISSN 0093-3813 Institutional research plan: CEZ:AV0Z30420517 Keywords : propagation spectrograms * whistlers Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.447, year: 2008

  7. Thermal effects on parallel resonance energy of whistler mode wave

    Indian Academy of Sciences (India)

    February 2006 physics pp. 467–472. Thermal effects on parallel resonance energy of whistler mode wave. DEVENDRAA SIINGH1, SHUBHA SINGH2 and R P SINGH2. 1Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pune 411 008, India. 2Department of Physics, Banaras Hindu University, Varanasi 221 ...

  8. Unidirectionally propagating whistler waves in the solar wind: Particle-in-cell simulations

    Science.gov (United States)

    Seough, J.

    2017-12-01

    The right-handed circularly polarized whistler fluctuations have often been observed in a free solar wind region. Interestingly, the measured whistlers propagate preferentially anti-sunward and appear to be characterized by nearly unidirectional propagation quasi-parallel to the local mean magnetic field at propagation angles smaller than 20o. Even though the solar wind electrons including the core and halo components possess temperature anisotropies that could drive the whistler instability, the free energy source of locally generated whistler waves is thought to be heat flux instability due to its unidirectional property. The purpose of this study is to present the possibility that not only heat flux instability but also whistler instability could be a local source of unidirectional whistler wave generation in the solar wind. By making use of both linear Vlasov analysis and electromagnetic particle-in-cell simulation, we show that unidirectionally propagating whistler waves can be naturally generated in situ by electron core temperature anisotropy-driven whistler instability when one takes into account the core-halo relative drift velocity in the proton rest frame. We also carry out particle-in-cell simulations of heat flux instability and compare between the two possible instabilities for understanding nonlinear property such as wave-particle interaction, especially halo electrons and whistler waves.

  9. Stimulated ion Compton scattering instability of whistlers in plasmas

    International Nuclear Information System (INIS)

    Shukla, P. K.; Shukla, Nitin; Stenflo, L.

    2006-01-01

    The nonlinear interactions between magnetic field-aligned broadband whistler wave packets (hereafter referred to as whistlerons) and ion quasimodes in magnetized plasmas are considered. By treating the whistlerons as quasiparticles, their nonlinear propagation in a slowly varying medium supported by ion quasimode density perturbations is studied. A nonlinear dispersion relation within the framework of the wave-kinetic (for the whistlerons) and Vlasov (for the ion quasimodes) descriptions is derived. The dispersion relation admits a kinetic modulational instability. The growth rate of the latter is presented. The present result can improve our understanding of the nonlinear propagation of incoherent whistlers, which have been frequently observed in the Earth's magnetosphere as well as in laboratory plasmas

  10. Effect of boundary conditions on radial mode structure of whistlers

    International Nuclear Information System (INIS)

    Boswell, R.W.

    1983-01-01

    The dispersion of the radical eigen modes of a cylindrical m=1 whistler wave with Ωsub(i) << ω << Ωsub(e) << ωsub(pe) are investigated for both conducting and insulating boundaries, where Ωsub(e) and Ωsub(i) are the electron and ion gyro frequencies, Ωsub(pe) is the electron plasma frequency. The effects of electron inertia and resistivity on the modes are discussed

  11. Nonlinear evolution of the modulational instability of whistler waves

    DEFF Research Database (Denmark)

    Karpman, V.I.; Hansen, F.R.; Huld, T.

    1990-01-01

    The nonlinear evolution of the modulational instability of whistler waves coupled to fast magnetosonic waves is investigated in two spatial dimensions by numerical simulations. The long time evolution of the modulational instability shows a quasirecurrent behavior with a slow spreading...... of the energy, originally confined to the lowest wave numbers, to larger and larger wave numbers resulting in an apparently chaotic or random wave field. © 1990 The American Physical Society...

  12. The Characteristic Response of Whistler Mode Waves to Interplanetary Shocks

    Science.gov (United States)

    Yue, Chao; Chen, Lunjin; Bortnik, Jacob; Ma, Qianli; Thorne, Richard M.; Angelopoulos, Vassilis; Li, Jinxing; An, Xin; Zhou, Chen; Kletzing, Craig; Reeves, Geoffrey D.; Spence, Harlan E.

    2017-10-01

    Magnetospheric whistler mode waves play a key role in regulating the dynamics of the electron radiation belts. Recent satellite observations indicate a significant influence of interplanetary (IP) shocks on whistler mode wave power in the inner magnetosphere. In this study, we statistically investigate the response of whistler mode chorus and plasmaspheric hiss to IP shocks based on Van Allen Probes and THEMIS satellite observations. Immediately after the IP shock arrival, chorus wave power is usually intensified, often at postmidnight to prenoon sector, while plasmaspheric hiss wave power predominantly decreases near the dayside but intensifies near the nightside. We conclude that chorus wave intensification outside the plasmasphere is probably associated with the suprathermal electron flux enhancement caused by the IP shock. Through a simple ray tracing modeling assuming the scenario that plasmaspheric hiss is originated from chorus, we find that the solar wind dynamic pressure increase changes the magnetic field configuration to favor ray penetration in the nightside and promote ray refraction away from the dayside, potentially explaining the magnetic local time-dependent responses of plasmaspheric hiss waves following IP shock arrivals.

  13. Interannual variation in methane emissions from tropical wetlands triggered by repeated El Niño Southern Oscillation

    Science.gov (United States)

    Zhu, Qiuan; Peng, Changhui; Ciais, Philippe; Jiang, Hong; Liu, Jinxun; Bousquet, Philippe; Li, Shiqin; Chang, Jie; Fang, Xiuqin; Zhou, Xiaolu; Chen, Huai; Liu, Shirong; Lin, Guanghui; Gong, Peng; Wang, Meng; Wang, Han; Xiang, Wenhua; Chen, Jing

    2017-01-01

    Methane (CH4) emissions from tropical wetlands contribute 60%–80% of global natural wetland CH4 emissions. Decreased wetland CH4 emissions can act as a negative feedback mechanism for future climate warming and vice versa. The impact of the El Niño–Southern Oscillation (ENSO) on CH4 emissions from wetlands remains poorly quantified at both regional and global scales, and El Niño events are expected to become more severe based on climate models’ projections. We use a process-based model of global wetland CH4 emissions to investigate the impacts of the ENSO on CH4 emissions in tropical wetlands for the period from 1950 to 2012. The results show that CH4 emissions from tropical wetlands respond strongly to repeated ENSO events, with negative anomalies occurring during El Niño periods and with positive anomalies occurring during La Niña periods. An approximately 8-month time lag was detected between tropical wetland CH4 emissions and ENSO events, which was caused by the combined time lag effects of ENSO events on precipitation and temperature over tropical wetlands. The ENSO can explain 49% of interannual variations for tropical wetland CH4 emissions. Furthermore, relative to neutral years, changes in temperature have much stronger effects on tropical wetland CH4 emissions than the changes in precipitation during ENSO periods. The occurrence of several El Niño events contributed to a lower decadal mean growth rate in atmospheric CH4 concentrations throughout the 1980s and 1990s and to stable atmospheric CH4 concentrations from 1999 to 2006, resulting in negative feedback to global warming.

  14. Evaluation of process conditions triggering emissions of green-house gases from a biological wastewater treatment system

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Caballero, A.; Aymerich, I. [Catalan Institute for Water Research (ICRA), Emili Grahit Street, 101, H_2O Building, Scientific and Technological Park of the University of Girona, 17003 Girona (Spain); Poch, M. [Laboratory of Chemical and Environmental Engineering (LEQUIA-UdG), Institute of the Environment, University of Girona, Campus Montilivi s/n, E-17071 Girona (Spain); Pijuan, M., E-mail: mpijuan@icra.cat [Catalan Institute for Water Research (ICRA), Emili Grahit Street, 101, H_2O Building, Scientific and Technological Park of the University of Girona, 17003 Girona (Spain)

    2014-09-15

    In this study, methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) emission dynamics of a plug–flow bioreactor located in a municipal full-scale wastewater treatment plant were monitored during a period of 10 weeks. In general, CH{sub 4} and N{sub 2}O gas emissions from the bioreactor accounted for 0.016% of the influent chemical oxygen demand (COD) and 0.116% of the influent total Kjeldahl nitrogen (TKN) respectively. In order to identify the emission patterns in the different zones, the bioreactor was divided in six different sampling sites and the gas collection hood was placed for a period of 2–3 days in each of these sites. This sampling strategy also allowed the identification of different process perturbations leading to CH{sub 4} or N{sub 2}O peak emissions. CH{sub 4} emissions mainly occurred in the first aerated site, and were mostly related with the influent and reject wastewater flows entering the bioreactor. On the other hand, N{sub 2}O emissions were given along all the aerated parts of the bioreactor and were strongly dependant on the occurrence of process disturbances such as periods of no aeration or nitrification instability. Dissolved CH{sub 4} and N{sub 2}O concentrations were monitored in the bioreactor and in other parts of the plant, as a contribution for the better understanding of the transport of these greenhouse gases across the different stages of the treatment system. - Highlights: • Monitoring of CH{sub 4} and N{sub 2}O emissions from a full-scale activated sludge bioreactor • Process perturbations leading to CH{sub 4} and N{sub 2}O peak emissions were identified. • Peak emissions increased severely the overall emission account of the bioreactor. • CH{sub 4} emissions were related with the inflow of influent and reject wastewater. • N{sub 2}O was generated as consequence of nitrification imbalances.

  15. X-ray Excitation Triggers Ytterbium Anomalous Emission in CaF 2 :Yb but Not in SrF 2 :Yb

    Energy Technology Data Exchange (ETDEWEB)

    Hughes-Currie, Rosa B.; Ivanovskikh, Konstantin V.; Wells, Jon-Paul R.; Reid, Michael F.; Gordon, Robert A.; Seijo, Luis; Barandiarán, Zoila

    2017-02-27

    Materials that luminesce after excitation with ionizing radiation are extensively applied in physics, medicine, security, and industry. Lanthanide dopants are known to trigger crystal scintillation through their fast d–f emissions; the same is true for other important applications as lasers or phosphors for lighting. However, this ability can be seriously compromised by unwanted anomalous emissions often found with the most common lanthanide activators. We report high-resolution X-ray-excited optical (IR to UV) luminescence spectra of CaF2:Yb and SrF2:Yb samples excited at 8949 eV and 80 K. Ionizing radiation excites the known anomalous emission of ytterbium in the CaF2 host but not in the SrF2 host. Wave function-based ab initio calculations of host-to-dopant electron transfer and Yb2+/Yb3+ intervalence charge transfer explain the difference. The model also explains the lack of anomalous emission in Yb-doped SrF2 excited by VUV radiation.

  16. On the Self-Focusing of Whistler Waves in a Radial Inhomogeneous Plasma

    DEFF Research Database (Denmark)

    Balmashnov, A. A.

    1980-01-01

    The process of whistler wave self-focusing is experimentally investigated. It was found that a whistler wave propagating along the plasma column with a density crest excites a longitudinal wave of the same frequency propagating across the external magnetic field. The amplitude modulation of the l......The process of whistler wave self-focusing is experimentally investigated. It was found that a whistler wave propagating along the plasma column with a density crest excites a longitudinal wave of the same frequency propagating across the external magnetic field. The amplitude modulation...... of the latter wave is accompanied by a density modification, which leads to trapping of the whistler wave in a density trough in the center of the plasma column....

  17. Effect of parallel electric fields on the whistler mode wave propagation in the magnetosphere

    International Nuclear Information System (INIS)

    Gupta, G.P.; Singh, R.N.

    1975-01-01

    The effect of parallel electric fields on whistler mode wave propagation has been studied. To account for the parallel electric fields, the dispersion equation has been analyzed, and refractive index surfaces for magnetospheric plasma have been constructed. The presence of parallel electric fields deforms the refractive index surfaces which diffuse the energy flow and produce defocusing of the whistler mode waves. The parallel electric field induces an instability in the whistler mode waves propagating through the magnetosphere. The growth or decay of whistler mode instability depends on the direction of parallel electric fields. It is concluded that the analyses of whistler wave records received on the ground should account for the role of parallel electric fields

  18. Direction finding of very-low-latitude whistlers and their propagation

    Science.gov (United States)

    Hayakawa, M.; Ohta, K.; Shimakura, S.

    Spaced direction finding measurements of very-low-latitude whistlers were carried out in January 1988 at three stations in South China; Zhanjiang (geomagnetic latitude 10.1 deg), Guilin (14.1 deg) and Wuchang (19.4 deg). Two horizontal magnetic and one vertical electric field components were simultaneously recorded over a wide frequency range to enable comprehensive direction finding. The analyses of whistler data on several days have indicated that the ionospheric transmission latitude of equatorial latitude whistlers is restricted to the geomagnetic latitude range of 10-14 deg, and the presence of high occurrence of echo-train whistlers is a strong indication of their field-aligned propagation. The propagation mechanism of very-low-latitude whistlers is discussed.

  19. The effect of subionospheric propagation on whistlers recorded by the DEMETER satellite – observation and modelling

    Directory of Open Access Journals (Sweden)

    O. E. Ferencz

    2007-06-01

    Full Text Available During a routine analysis of whistlers on the wide-band VLF recording of the DEMETER satellite, a specific signal structure of numerous fractional-hop whistlers, termed the "Spiky Whistler" (SpW was identified. These signals appear to be composed of a conventional whistler combined by the compound mode-patterns of guided wave propagation, suggesting a whistler excited by a lightning "tweek" spheric. Rigorous, full-wave modelling of tweeks, formed by the long subionospheric guided spheric propagation and of the impulse propagation across an arbitrarily inhomogeneous ionosphere, gave an accurate description of the SpW signals. The electromagnetic impulses excited by vertical, preferably CG lightning discharge, exhibited the effects of guided behaviour and of the dispersive ionospheric plasma along their paths. This modelling and interpretation provides a consistent way to determine the generation and propagation characteristics of the recorded SpW signals, as well as to describe the traversed medium.

  20. Particle-in-cell Simulation of Dipolarization Front Associated Whistlers

    Science.gov (United States)

    Lin, D.; Scales, W.; Ganguli, G.; Crabtree, C. E.

    2017-12-01

    Dipolarization fronts (DFs) are dipolarized magnetic field embedded in the Earthward propagating bursty bulk flows (BBFs), which separates the hot, tenuous high-speed flow from the cold, dense, and slowly convecting surrounding plasma [Runov et al. 2011]. Broadband fluctuations have been observed at DFs including the electromagnetic whistler waves and electrostatic lower hybrid waves in the Very Low Frequency (VLF) range [e.g., Zhou et al. 2009, Deng et al. 2010]. There waves are suggested to be able heat electrons and play a critical role in the plasma sheet dynamics [Chaston et al., 2012, Angelopoulos et al., 2013]. However, their generation mechanism and role in the energy conversion are still under debate. The gradient scale of magnetic field, plasma density at DFs in the near-Earth magnetotail is comparable to or lower than the ion gyro radius [Runov et al., 2011, Fu et al., 2012, Breuillard et al., 2016]. Such strongly inhomogeneous configuration could be unstable to the electron-ion hybrid (EIH) instability, which arises from strongly sheared transverse flow and is in the VLF range [Ganguli et al. 1988, Ganguli et al. 2014]. The equilibrium of the EIH theory implies an anisotropy of electron temperature, which are likely to drive the whistler waves observed in DFs [Deng et al., 2010, Gary et al., 2011]. In order to better understand how the whistler waves are generated in DFs and whether the EIH theory is applicable, a fully electromagnetic particle-in-cell (EMPIC) model is used to simulate the EIH instability with similar equilibrium configurations in DF observations. The EMPIC model deals with three dimensions in the velocity space and two dimensions in the configuration space, which is quite ready to include the third configuration dimension. Simulation results will be shown in this presentation.

  1. Analysis of subprotonospheric whistlers observed by DEMETER: A case study

    Czech Academy of Sciences Publication Activity Database

    Chum, Jaroslav; Santolík, Ondřej; Parrot, M.

    2009-01-01

    Roč. 114, A02 (2009), A02307/1-A02307/17 ISSN 0148-0227 R&D Projects: GA ČR GA205/06/1267; GA ČR GA205/06/0875; GA AV ČR IAA300420603; GA AV ČR IAA301120601 Grant - others:Lapland Atmosphere- Biosphere Facility - 2 (LAPBIAT-2)(XE) RITA-CT-2006-025969 Institutional research plan: CEZ:AV0Z30420517 Keywords : waves in plasma * propagation and reflection of lightning induced whistlers * ion composition in the upper ionosphere Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.082, year: 2009

  2. Whistler Wave Propagation Through the Ionosphere of Venus

    Science.gov (United States)

    Pérez-Invernón, F. J.; Lehtinen, N. G.; Gordillo-Vázquez, F. J.; Luque, A.

    2017-11-01

    We investigate the attenuation of whistler waves generated by hypotetical Venusian lightning occurring at the altitude of the cloud layer under different ionospheric conditions. We use the Stanford full-wave method for stratified media of Lehtinen and Inan (2008) to model wave propagation through the ionosphere of Venus. This method calculates the electromagnetic field created by an arbitrary source in a plane-stratified medium (i.e., uniform in the horizontal direction). We see that the existence of holes in electronic densities and the magnetic field configuration caused by solar wind play an important role in the propagation of electromagnetic waves through the Venusian ionosphere.

  3. TRANS-TEXTUALIZATION AND CARNIVALIZATION IN "WHISTLER," BY ONDJAKI

    Directory of Open Access Journals (Sweden)

    Karine Miranda Campos

    2013-04-01

    Full Text Available This article aims to observe the phenomenon of carnivalization and trans­textuality the novel The Whistler, the Angolan writer Ondjaki. Comprise the theoretical analysis of Bakhtin’s theory on carnivalization and its im­portance for social subversion of monologic discourse established by of­ficial bodies, the theory of Gérard Genette on transtextuality pointing five possible textual relationships. An understanding of the theories and car­nivalization transtextuality pervades the concepts of animism and taboo presented the theory of Sigmund Freud.

  4. Source attribution of aerosol size distributions and model evaluation using Whistler Mountain measurements and GEOS-Chem-TOMAS simulations

    Science.gov (United States)

    D'Andrea, S. D.; Ng, J. Y.; Kodros, J. K.; Atwood, S. A.; Wheeler, M. J.; Macdonald, A. M.; Leaitch, W. R.; Pierce, J. R.

    2016-01-01

    Remote and free-tropospheric aerosols represent a large fraction of the climatic influence of aerosols; however, aerosol in these regions is less characterized than those polluted boundary layers. We evaluate aerosol size distributions predicted by the GEOS-Chem-TOMAS global chemical transport model with online aerosol microphysics using measurements from the peak of Whistler Mountain, British Columbia, Canada (2182 m a.s.l., hereafter referred to as Whistler Peak). We evaluate the model for predictions of aerosol number, size, and composition during periods of free-tropospheric (FT) and boundary-layer (BL) influence at "coarse" 4° × 5° and "nested" 0.5° × 0.667° resolutions by developing simple FT/BL filtering techniques. We find that using temperature as a proxy for upslope flow (BL influence) improved the model-measurement comparisons. The best threshold temperature was around 2 °C for the coarse simulations and around 6 °C for the nested simulations, with temperatures warmer than the threshold indicating boundary-layer air. Additionally, the site was increasingly likely to be in cloud when the measured relative humidity (RH) was above 90 %, so we do not compare the modeled and measured size distributions during these periods. With the inclusion of these temperature and RH filtering techniques, the model-measurement comparisons improved significantly. The slope of the regression for N80 (the total number of particles with particle diameter, Dp, > 80 nm) in the nested simulations increased from 0.09 to 0.65, R2 increased from 0.04 to 0.46, and log-mean bias improved from 0.95 to 0.07. We also perform simulations at the nested resolution without Asian anthropogenic emissions and without biomass-burning emissions to quantify the contribution of these sources to aerosols at Whistler Peak (through comparison with simulations with these emissions on). The long-range transport of Asian anthropogenic aerosol was found to be significant throughout all particle

  5. Whistler Mode Waves and the Electron Heat Flux in the Solar Wind: Cluster Observations

    Science.gov (United States)

    Lacombe, C.; Alexandrova, O.; Matteini, L.; Santolík, O.; Cornilleau-Wehrlin, N.; Mangeney, A.; de Conchy, Y.; Maksimovic, M.

    2014-11-01

    The nature of the magnetic field fluctuations in the solar wind between the ion and electron scales is still under debate. Using the Cluster/STAFF instrument, we make a survey of the power spectral density and of the polarization of these fluctuations at frequencies f in [1, 400] Hz, during five years (2001-2005), when Cluster was in the free solar wind. In ~10% of the selected data, we observe narrowband, right-handed, circularly polarized fluctuations, with wave vectors quasi-parallel to the mean magnetic field, superimposed on the spectrum of the permanent background turbulence. We interpret these coherent fluctuations as whistler mode waves. The lifetime of these waves varies between a few seconds and several hours. Here, we present, for the first time, an analysis of long-lived whistler waves, i.e., lasting more than five minutes. We find several necessary (but not sufficient) conditions for the observation of whistler waves, mainly a low level of background turbulence, a slow wind, a relatively large electron heat flux, and a low electron collision frequency. When the electron parallel beta factor β e∥ is larger than 3, the whistler waves are seen along the heat flux threshold of the whistler heat flux instability. The presence of such whistler waves confirms that the whistler heat flux instability contributes to the regulation of the solar wind heat flux, at least for β e∥ >= 3, in slow wind at 1 AU.

  6. Whistler mode waves and the electron heat flux in the solar wind: cluster observations

    Energy Technology Data Exchange (ETDEWEB)

    Lacombe, C.; Alexandrova, O.; Cornilleau-Wehrlin, N.; Mangeney, A.; De Conchy, Y.; Maksimovic, M. [LESIA, Observatoire de Paris, PSL Research University, CNRS, UPMC Université Paris 06, Université Paris-Diderot, 5 Place Jules Janssen, F-92190 Meudon (France); Matteini, L. [Imperial College, London SW7 2AZ (United Kingdom); Santolík, O. [Institute of Atmospheric Physics ASCR, 141 31 Prague (Czech Republic)

    2014-11-20

    The nature of the magnetic field fluctuations in the solar wind between the ion and electron scales is still under debate. Using the Cluster/STAFF instrument, we make a survey of the power spectral density and of the polarization of these fluctuations at frequencies f in [1, 400] Hz, during five years (2001-2005), when Cluster was in the free solar wind. In ∼10% of the selected data, we observe narrowband, right-handed, circularly polarized fluctuations, with wave vectors quasi-parallel to the mean magnetic field, superimposed on the spectrum of the permanent background turbulence. We interpret these coherent fluctuations as whistler mode waves. The lifetime of these waves varies between a few seconds and several hours. Here, we present, for the first time, an analysis of long-lived whistler waves, i.e., lasting more than five minutes. We find several necessary (but not sufficient) conditions for the observation of whistler waves, mainly a low level of background turbulence, a slow wind, a relatively large electron heat flux, and a low electron collision frequency. When the electron parallel beta factor β {sub e∥} is larger than 3, the whistler waves are seen along the heat flux threshold of the whistler heat flux instability. The presence of such whistler waves confirms that the whistler heat flux instability contributes to the regulation of the solar wind heat flux, at least for β {sub e∥} ≥ 3, in slow wind at 1 AU.

  7. Excitation of Banded Whistler Waves in the Magnetosphere

    Energy Technology Data Exchange (ETDEWEB)

    Gary, S. Peter [Los Alamos National Laboratory; Liu, Kaijun [Los Alamos National Laboratory; Winske, Dan [Los Alamos National Laboratory

    2012-07-13

    Banded whistler waves can be generated by the whistler anisotropy instability driven by two bi-Maxwellian electron components with T{sub {perpendicular}}/T{sub {parallel}} > 1 at different T{sub {parallel}} For typical magnetospheric condition of 1 < {omega}{sub e}/{Omega}{sub e} < 5 in regions associated with strong chorus, upper-band waves can be excited by anisotropic electrons below {approx} 1 keV, while lower-band waves are excited by anisotropic electrons above {approx} 10 keV. Lower-band waves are generally field-aligned and substantially electromagnetic, while upper-band waves propagate obliquely and have quasi-electrostatic fluctuating electric fields. The quasi-electrostatic feature of upper-band waves suggests that they may be more easily identified in electric field observations than in magnetic field observations. Upper-band waves are liable to Landau damping and the saturation level of upperband waves is lower than lower-band waves, consistent with observations that lower-band waves are stronger than upper-band waves on average. The oblique propagation, the lower saturation level, and the more severe Landau damping together would make upper-band waves more tightly confined to the geomagnetic equator (|{lambda}{sub m}| < {approx}10{sup o}) than lower-band waves.

  8. Solar Wind Electron Scattering by Kinetic Instabilities and Whistler Turbulence

    Science.gov (United States)

    Gary, S. P.

    2015-12-01

    The expansion of the solar wind away from the Sun drives electron velocity distributions away from the thermal Maxwellian form, yielding distributions near 1 AU which typically can be characterized as consisting of three anisotropic components: a more dense, relatively cool core, a relatively tenuous , relatively warm halo and a similarly tenuous, warm strahl. Each of these nonthermal components are potential sources of kinetic plasma instabilities; the enhanced waves from each instability can scatter the electrons, acting to reduce the various anisotropies and making their overall velocity distribution more nearly (but not completely) thermal. In contrast, simulations are demonstrating that the forward decay of whistler turbulence can lead to the development of a T||> T_perp electron anisotropy. This presentation will review linear theories of electron-driven kinetic instabilities (following the presentation by Daniel Verscharen at the 2015 SHINE Workshop), and will further consider the modification of electron velocity distributions as obtained from particle-in-cell simulations of such instabilities as well as from the decay of whistler turbulence.

  9. Trigger finger

    Science.gov (United States)

    ... digit; Trigger finger release; Locked finger; Digital flexor tenosynovitis ... cut or hand Yellow or green drainage from the cut Hand pain or discomfort Fever If your trigger finger returns, call your surgeon. You may need another surgery.

  10. Electron cyclotron emission from energetic electrons in TMX-upgrade

    International Nuclear Information System (INIS)

    Ellis, R.F.; James, R.; Lasnier, C.J.; Casper, T.A.

    1984-01-01

    Measurements are reported of electron cyclotron emission from the mirror confined energetic electrons confined in the end cells of TMX-U. Electron cyclotron emission is measured both nearly parallel to the magnetic field (whistler emission) and nearly perpendicular to the magnetic field. Whistler emission has been measured in the East end cell in the frequency range 12-18 GHz, which corresponds to fundamental emission near the bottom of the magnetic well (f/sub c/ at midplane = 14 GHz). The results are compared with a radiation transfer model. Agreement between the whistler measurements and the model are quite good and confirm that the whistler emission is generally optically thick and that an average perpendicular temperature for the hot component can be measured if the cold component density is not too high. Perpendicular emission has been measured in both end cells in the frequency ranges 30-40 GHz (2-3 harmonic) and 56-70 GHz (4-5 harmonic). The perpendicular emission is generally optically thin and can reveal information about the time history of the energetic electron density and energy spectrum. The results are compared with a model of cyclotron emission valid for low density plasma of arbitrary distribution function. Nonthermal emissions caused by microinstabilities are to be discussed

  11. Nonlinear evolution of oblique whistler waves in radiation belts

    Science.gov (United States)

    Sharma, R. P.; Nandal, P.; Yadav, N.; Sharma, Swati

    2017-02-01

    Magnetic power spectrum and formation of coherent structures have been investigated in the present work applicable to Van Allen radiation belt. The nonlinear interaction of high frequency oblique whistler wave and low frequency magnetosonic wave has been investigated. Simulation was performed of the coupled equation of these two waves. The nonlinear interaction of these waves leads to the formation of the localized structures. These resulting localized structures are of complex nature. The associated magnetic power spectrum has also been studied. Dispersive nonlinear processes account for the high frequency part of the spectrum. The resulting magnetic power spectrum shows a scaling of k^{ - 4.5}. The energy transfer process from injection scales to smaller scales is explained by the results.

  12. Whistler waves, core ion heating, and nonstationarity in oblique collisionless shocks

    International Nuclear Information System (INIS)

    Scholer, Manfred; Burgess, David

    2007-01-01

    One-dimensional full particle simulations of supercritical collisionless shocks with an ion and electron beta of 0.1 (particle to magnetic field pressure) over a wide Alfven Mach number range and range of shock normal-magnetic field angles between Θ Bn =60 deg. and Θ Bn =80 deg. are presented. The whistler critical Mach number M w , below which a linear phase-standing whistler can exist, is proportional to the square root of the ion-to-electron mass ratio and to cos Θ Bn . In small mass ratio simulations of oblique shocks, M w can be artificially small and close to the first critical Mach number M c , above which the process of ion reflection is needed in order to achieve shock dissipation. We use in the simulations the physical ion-to-electron mass ratio so that M c and M w are well separated. This also allows excitation of the modified two-stream instability (MTSI) between incoming ions and electrons. We find that in oblique but close to perpendicular (Θ Bn ≥80 deg.) shocks, upstream whistler waves do occur, but reformation is due to accumulation of reflected-gyrating ions at the upstream edge of the foot. In less oblique shocks above the whistler critical Mach number, the whistler amplitude in the foot upstream of the ramp grows, leading to vortices of the incoming ions and the reflected ions in velocity phase space, and eventually to phase mixing. The shock re-forms at the upstream edge of the whistler wave train, which is particularly evident in very high Mach number shocks where the scale of the foot is large compared with the whistler wave train. After reformation, the region with phase-mixed incoming and reflected ions constitutes a hot core downstream of the shock ramp. In this whistler induced reformation process, the MTSI results mainly in heating of the incoming ions in the foot

  13. Precipitation of Trapped Relativistic Electrons by Amplified Whistler Waves in the Magnetosphere

    Science.gov (United States)

    2007-06-01

    From - To) 27-06-2007 1 REPRINT I 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Precipitation of trapped relativistic electrons by amplified whistler waves...in the magnetosphere 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62101F 6. AUTHORS 5d. PROJECT NUMBER S.P. Kuo*, Steven S. Kuo**, James T. Huynh...Airborne Systems, El Segundo, CA 90245 14. ABSTRACT Numerical study of a loss-cone negative mass instability to amplify whistler waves by energewtic

  14. THE ALGORITHM FOR THE AUTOMATIC DETECTION OF THE WHISTLERS IN THE REAL-TIME MODE

    Directory of Open Access Journals (Sweden)

    E.A. Malysh

    2015-12-01

    Full Text Available This is the description of the whistlers automatic detection algorithm, based on the nonlinear transformation of the spectrogram VLF signal. In the converted spectrogram the whistler graphic is presented by a straight line, detection of which is algorithmically simple task. The testing of the program implementation of the algorithm showed that a detection can be managed in the real-time mode.

  15. Talking Trash: the politics of sustainability and waste management in Whistler, British Columbia

    OpenAIRE

    Temenos, Cristina

    2007-01-01

    In 2005, the Resort Municipality of Whistler, British Columbia began shipping its solid waste to a landfill in Redmond, Washington as part of its solid waste management program. According to the municipality this practice is in line with Whistler 2020, its fifteen-year comprehensive sustainability plan, adopted in 2004. Whistler’s waste management policy and practices raise questions of municipal, citizen, business, and visitor responsibility regarding waste management and sustainability in r...

  16. Generation of Electron Whistler Waves at the Mirror Mode Magnetic Holes: MMS Observations and PIC Simulation

    OpenAIRE

    Ahmadi, Narges; Wilder, Frederick; Ergun, Robert; Argall, Matthew; Usanova, Maria; Breuillard, Hugo; Malaspina, David; Paulson, Kristoff; Germaschewski, Kai; Eriksson, Stefan; Goodrich, Katherine; Torbert, Roy; Contel, Olivier Le; Strangeway, Robert; Russell, Christopher

    2018-01-01

    The Magnetospheric Multiscale (MMS) mission has observed electron whistler waves at the center and at the edges of magnetic holes in the dayside magnetosheath. The magnetic holes are nonlinear mirror structures since their magnitude is anti-correlated with particle density. In this article, we examine the growth mechanisms of these whistler waves and their interaction with the host magnetic hole. In the observations, as magnetic holes develop and get deeper, an electron population gets trappe...

  17. The producing of an ECR plasma using 2450MHz Whistler Wave and the investigating of its parameters

    International Nuclear Information System (INIS)

    Fang Yude; Zhang Jiande; Fu Keming; Lu Xiangyu; Liu Dengcheng; Wang Xianyu; Xie Weidong; Bao Dinghua; Yin Xiejin

    1988-12-01

    A stable ECR plasma was produced and sustained in HER mirror using 2450MHz Whistler wave. The parameters of the ECR plasma and their chaining characters were studied in detail and were compared with those of the DC discharge plasmas. The conclusion is that the ECR plasma is a high ionizability, low temperature, middle density plasma, its peak density may much exceed the cutoff density of the pump wave (when ω = ω pe ) and arrive at the order of 10 12 cm -3 . The ECR plasma includes some high energy hot electrons (20Kev-200Kev) and middle energy warm electrons (< 20Kev). Those two kinds of electron created some strong X-ray emissions in a wide frequency range. The ECR plasma has higher edge density and can strongly interact with the wall. (author). 9 refs, 17 figs

  18. Frequencies of wave packets of whistler-mode chorus inside its source region: a case study

    Directory of Open Access Journals (Sweden)

    O. Santolik

    2008-06-01

    Full Text Available Whistler-mode chorus is a structured wave emission observed in the Earth's magnetosphere in a frequency range from a few hundreds of Hz to several kHz. We investigate wave packets of chorus using high-resolution measurements recorded by the WBD instrument on board the four Cluster spacecraft. A night-side chorus event observed during geomagnetically disturbed conditions is analyzed. We identify lower and upper frequencies for a large number of individual chorus wave packets inside the chorus source region. We investigate how these observations are related to the central position of the chorus source which has been previously estimated from the Poynting flux measurements. We observe typical frequency bandwidths of chorus of approximately 10% of the local electron cyclotron frequency. Observed time scales are around 0.1 s for the individual wave packets. Our results indicate a lower occurrence probability for lower frequencies in the vicinity of the central position of the source compared to measurements recorded closer to the outer boundaries of the source. This is in agreement with recent research based on the backward wave oscillator theory.

  19. VLF emissions from ionospheric/magnetospheric plasma

    Indian Academy of Sciences (India)

    It is argued that most of the emissions are generated during Doppler shifted cyclotron resonance interaction between the whistler mode wave and counter streaming energetic electrons. Resonance energy of the participating electron and interaction length are evaluated to explain the generation mechanism of some of these ...

  20. Whistler oscillitons revisited: the role of charge neutrality?

    Directory of Open Access Journals (Sweden)

    F. Verheest

    2004-01-01

    Full Text Available When studying transverse modes propagating parallel to a static magnetic field, an apparent contradiction arises between the weakly nonlinear results obtained from the derivative nonlinear Schrödinger equation, predicting envelope solitons (where the amplitude is stationary in the wave frame, but the phase is not, and recent results for whistler oscillitons, indicating that really stationary structures of large amplitude are possible. Revisiting this problem in the fluid dynamic approach, care has been taken not to introduce charge neutrality from the outset, because this not only neglects electric stresses compared to magnetic stresses, which is reasonable, but could also imply from Poisson's equation a vanishing of the wave electric field. Nevertheless, the fixed points of the remaining equations are the same, whether charge neutrality is assumed from the outset or not, so that the solitary wave solutions at not too large amplitudes will be very similar. This is borne out by numerical simulations of the solutions under the two hypotheses, showing that the lack of correspondence with the DNLS envelope solitons indicates the limitations of the reductive perturbation approach, and is not a consequence of assuming charge neutrality.

  1. Control of runaway electron energy using externally injected whistler waves

    Science.gov (United States)

    Guo, Zehua; McDevitt, Christopher J.; Tang, Xian-Zhu

    2018-03-01

    One way of mitigating runaway damage of the plasma-facing components in a tokamak fusion reactor is by limiting the runaway electron energy under a few MeV, while not necessarily reducing the runaway current appreciably. Here, we describe a physics mechanism by which such momentum space engineering of the runaway distribution can be facilitated by externally injected high-frequency electromagnetic waves such as whistler waves. The drastic impact that wave-induced scattering can have on the runaway energy distribution is fundamentally the result of its ability to control the runaway vortex in the momentum space. The runaway vortex, which is a local circulation of runaways in momentum space, is the outcome of the competition between Coulomb collisions, synchrotron radiation damping, and runaway acceleration by the parallel electric field. By introducing a wave that resonantly interacts with runaways in a particular range of energies which is mildly relativistic, the enhanced scattering would reshape the vortex by cutting off the part that is highly relativistic. The efficiency of resonant scattering accentuates the requirement that the wave amplitude can be small so the power requirement from external wave injection is practical for the mitigation scheme.

  2. Parameter spaces for linear and nonlinear whistler-mode waves

    International Nuclear Information System (INIS)

    Summers, Danny; Tang, Rongxin; Omura, Yoshiharu; Lee, Dong-Hun

    2013-01-01

    We examine the growth of magnetospheric whistler-mode waves which comprises a linear growth phase followed by a nonlinear growth phase. We construct time-profiles for the wave amplitude that smoothly match at the transition between linear and nonlinear wave growth. This matching procedure can only take place over a limited “matching region” in (N h /N 0 ,A T )-space, where A T is the electron thermal anisotropy, N h is the hot (energetic) electron number density, and N 0 is the cold (background) electron number density. We construct this matching region and determine how the matching wave amplitude varies throughout the region. Further, we specify a boundary in (N h /N 0 ,A T )-space that separates a region where only linear chorus wave growth can occur from the region in which fully nonlinear chorus growth is possible. We expect that this boundary should prove of practical use in performing computationally expensive full-scale particle simulations, and in interpreting experimental wave data

  3. An Experimental Investigation of the Whistler Nozzle and an Analytical Investigation of a Ring Wing in Supersonic Flow

    Science.gov (United States)

    1976-03-01

    19. KEY WORDS ( Continuo on rovors* ad*e It noc~e..q etid Identif). by’ block numbs:) Ring 5 A•fi, Whistler-iT8_zle, Entai~n_,aent, ThrustAutg-tatioh...RESEARCH The intent of this research was to provide a clearer insight into the workings of the whistler nozzle, and to develop an improved

  4. The Role of Higher-Order Modes on the Electromagnetic Whistler-Cyclotron Wave Fluctuations of Thermal and Non-Thermal Plasmas

    Science.gov (United States)

    Vinas, Adolfo F.; Moya, Pablo S.; Navarro, Roberto; Araneda, Jamie A.

    2014-01-01

    Two fundamental challenging problems of laboratory and astrophysical plasmas are the understanding of the relaxation of a collisionless plasmas with nearly isotropic velocity distribution functions and the resultant state of nearly equipartition energy density with electromagnetic plasma turbulence. Here, we present the results of a study which shows the role that higher-order-modes play in limiting the electromagnetic whistler-like fluctuations in a thermal and non-thermal plasma. Our main results show that for a thermal plasma the magnetic fluctuations are confined by regions that are bounded by the least-damped higher order modes. We further show that the zone where the whistler-cyclotron normal modes merges the electromagnetic fluctuations shifts to longer wavelengths as the beta(sub e) increases. This merging zone has been interpreted as the beginning of the region where the whistler-cyclotron waves losses their identity and become heavily damped while merging with the fluctuations. Our results further indicate that in the case of nonthermal plasmas, the higher-order modes do not confine the fluctuations due to the effective higher-temperature effects and the excess of suprathermal plasma particles. The analysis presented here considers the second-order theory of fluctuations and the dispersion relation of weakly transverse fluctuations, with wave vectors parallel to the uniform background magnetic field, in a finite temperature isotropic bi-Maxwellian and Tsallis-kappa-like magnetized electron-proton plasma. Our results indicate that the spontaneously emitted electromagnetic fluctuations are in fact enhanced over these quasi modes suggesting that such modes play an important role in the emission and absorption of electromagnetic fluctuations in thermal or quasi-thermal plasmas.

  5. EXPERIMENTAL DETERMINATION OF WHISTLER WAVE DISPERSION RELATION IN THE SOLAR WIND

    Energy Technology Data Exchange (ETDEWEB)

    Stansby, D.; Horbury, T. S.; Chen, C. H. K.; Matteini, L., E-mail: david.stansby14@imperial.ac.uk [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom)

    2016-09-20

    The origins and properties of large-amplitude whistler wavepackets in the solar wind are still unclear. In this Letter, we utilize single spacecraft electric and magnetic field waveform measurements from the ARTEMIS mission to calculate the plasma frame frequency and wavevector of individual wavepackets over multiple intervals. This allows direct comparison of experimental measurements with theoretical dispersion relations to identify the observed waves as whistler waves. The whistlers are right-hand circularly polarized, travel anti-sunward, and are aligned with the background magnetic field. Their dispersion is strongly affected by the local electron parallel beta in agreement with linear theory. The properties measured are consistent with the electron heat flux instability acting in the solar wind to generate these waves.

  6. Influence of a plasma hot component on whistler propagation beyond the plasmapause

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, A. (Instituto Superior Tecnico, Lisbon (Portugal). Centro de Electrodinamica)

    1982-10-01

    Theoretical spectrograms are computed for whistlers propagating beyond the plasmapause. The electron distribution function was modelled as consisting of a hot plus a cold component and an appropriate dispersion equation is used. A collisionless (CL) model is used for the cold electron concentration and for the hot electron component the derived model assumes a bi-maxwellian distribution function with a loss cone at the equator. The results indicate limits on the use of the cold plasma approximation (c.p.a.) in the study of magnetospheric whistler propagation beyond the plasmapause and show that whistler analysis with the c.p.a. may under or overestimate the L value of the path deduced from ground spectrograms, depending on the anisotropy of the hot component.

  7. Suppression of Electron Thermal Conduction by Whistler Turbulence in a Sustained Thermal Gradient

    Science.gov (United States)

    Roberg-Clark, G. T.; Drake, J. F.; Reynolds, C. S.; Swisdak, M.

    2018-01-01

    The dynamics of weakly magnetized collisionless plasmas in the presence of an imposed temperature gradient along an ambient magnetic field is explored with particle-in-cell simulations and modeling. Two thermal reservoirs at different temperatures drive an electron heat flux that destabilizes off-angle whistler-type modes. The whistlers grow to large amplitude, δ B /B0≃1 , and resonantly scatter the electrons, significantly reducing the heat flux. Surprisingly, the resulting steady-state heat flux is largely independent of the thermal gradient. The rate of thermal conduction is instead controlled by the finite propagation speed of the whistlers, which act as mobile scattering centers that convect the thermal energy of the hot reservoir. The results are relevant to thermal transport in high-β astrophysical plasmas such as hot accretion flows and the intracluster medium of galaxy clusters.

  8. Contemporaneous EMIC and whistler mode waves: Observations and consequences for MeV electron loss

    Science.gov (United States)

    Zhang, X.-J.; Mourenas, D.; Artemyev, A. V.; Angelopoulos, V.; Thorne, R. M.

    2017-08-01

    The high variability of relativistic (MeV) electron fluxes in the Earth's radiation belts is partly controlled by loss processes involving resonant interactions with electromagnetic ion cyclotron (EMIC) and whistler mode waves. But as previous statistical models were generated independently for each wave mode, whether simultaneous electron scattering by the two wave types has global importance remains an open question. Using >3 years of simultaneous Van Allen Probes and THEMIS measurements, we explore the contemporaneous presence of EMIC and whistler mode waves in the same L shell, albeit at different local times, determining the distribution of wave and plasma parameters as a function of L, Kp, and AE. We derive electron lifetimes from observations and provide the first statistics of combined effects of EMIC and whistler mode wave scattering on MeV electrons as a function of L and geomagnetic activity. We show that MeV electron lifetimes are often strongly reduced by such combined scattering.

  9. Examining Coherency Scales, Substructure, and Propagation of Whistler Mode Chorus Elements With Magnetospheric Multiscale (MMS)

    Science.gov (United States)

    Turner, D. L.; Lee, J. H.; Claudepierre, S. G.; Fennell, J. F.; Blake, J. B.; Jaynes, A. N.; Leonard, T.; Wilder, F. D.; Ergun, R. E.; Baker, D. N.; Cohen, I. J.; Mauk, B. H.; Strangeway, R. J.; Hartley, D. P.; Kletzing, C. A.; Breuillard, H.; Le Contel, O.; Khotyaintsev, Yu. V.; Torbert, R. B.; Allen, R. C.; Burch, J. L.; Santolik, O.

    2017-11-01

    Whistler mode chorus waves are a naturally occurring electromagnetic emission observed in Earth's magnetosphere. Here, for the first time, data from NASA's Magnetospheric Multiscale (MMS) mission were used to analyze chorus waves in detail, including the calculation of chorus wave normal vectors, fi>k. A case study was examined from a period of substorm activity around the time of a conjunction between the MMS constellation and NASA's Van Allen Probes mission on 07 April 2016. Chorus wave activity was simultaneously observed by all six spacecraft over a broad range of L shells (5.5 flat or falling frequency following the peak, and all the elements exhibited complex and well-organized substructure observed consistently at all four MMS spacecraft at separations up to 70 km (60 km perpendicular and 38 km parallel to the background magnetic field). The waveforms in field-aligned coordinates also demonstrated that these waves were all phase coherent, allowing for the direct calculation of fi>k. Error estimates on calculated fi>k revealed that the plane wave approximation was valid for six of the eight elements and most of the subelements. The wave normal vectors were within 20-30° from the direction antiparallel to the background field for all elements and changed from subelement to subelement through at least two of the eight elements. The azimuthal angle of fi>k in the perpendicular plane was oriented earthward and was oblique to that of the Poynting vector, which has implications for the validity of cold plasma theory.

  10. Nonlinear whistler wave model for lion roars in the Earth’s magnetosheath

    DEFF Research Database (Denmark)

    Dwivedi, N. K.; Singh, S.

    2017-01-01

    In the present study, we construct a nonlinear whistler wave model to explain the magnetic field spectra observed for lion roars in the Earth’s magnetosheath region. We use two-fluid theory and semi-analytical approach to derive the dynamical equation of whistler wave propagating along the ambient...... spectrum with a spectral slope of −4.5 superimposed with a narrow band peak. The broadband fluctuations appear due to the energy cascades attributed by low-frequency magnetohydrodynamic modes, whereas, a narrow band peak is observed due to the short period lion roars bursts. The energy spectrum predicted...

  11. Modeling Whistler Wave Generation Regimes In Magnetospheric Cyclotron Maser

    Science.gov (United States)

    Pasmanik, D. L.; Demekhov, A. G.; Trakhtengerts, V. Y.; Parrot, M.

    Numerical analysis of the model for cyclotron instability development in the Earth magnetosphere is made.This model, based on the self-consistent set of equations of quasi-linear plasma theory, describes different regimes of wave generation and related energetic particle precipitation. As the source of free energy the injection of energetic electrons with transverse anisotropic distribution function to the interaction region is considered. Two different mechanisms of energetic electron loss from the interaction region are discussed. The first one is precipitation of energetic particles via the loss cone. The other mechanism is drift of particles away from the interaction region across the mag- netic field line. In the case of interaction in plasmasphere or rather large areas of cold plasma density enhancement the loss cone precipitation are dominant. For interaction in a subauroral duct losses due to drift are most effective. A parametric study of the model for both mechanisms of particle losses is made. The main attention is paid to the analysis of generation regimes for different characteristics of energetic electron source, such as the shape of pitch-angle distributions and elec- tron density. We show that in addition to the well-known stationary generation and periodic regime with successive spikes of similar shape, more complex forms of wave spectrum exist. In particular, we found a periodic regime, in which a single period in- cludes two separate spikes with different spectral shapes. In another regime, periodic generation of spikes at higher frequencies together with quasi-stationary generation at lower frequencies occurs. Quasi-periodic regime with spike overlapping, i.e. when generation of a new spike begins before the previous one is over is also found. Results obtained are compared with experimental data on quasi-periodic regimes of whistler wave generation.

  12. Effects of whistler mode hiss waves in March 2013

    Science.gov (United States)

    Ripoll, J.-F.; Santolík, O.; Reeves, G. D.; Kurth, W. S.; Denton, M. H.; Loridan, V.; Thaller, S. A.; Kletzing, C. A.; Turner, D. L.

    2017-07-01

    We present simulations of the loss of radiation belt electrons by resonant pitch angle diffusion caused by whistler mode hiss waves for March 2013. Pitch angle diffusion coefficients are computed from the wave properties and the ambient plasma data obtained by the Van Allen Probes with a resolution of 8 h and 0.1 L shell. Loss rates follow a complex dynamic structure, imposed by the wave and plasma properties. Hiss effects can be strong, with minimum lifetimes (of 1 day) moving from energies of 100 keV at L 5 up to 2 MeV at L 2 and stop abruptly, similarly to the observed energy-dependent inner belt edge. Periods when the plasmasphere extends beyond L 5 favor long-lasting hiss losses from the outer belt. Such loss rates are embedded in a reduced Fokker-Planck code and validated against Magnetic Electron and Ion Spectrometer observations of the belts at all energy. Results are complemented with a sensitivity study involving different radial diffusion and lifetime models. Validation is carried out globally at all L shells and energies. The good agreement between simulations and observations demonstrates that hiss waves drive the slot formation during quiet times. Combined with transport, they sculpt the energy structure of the outer belt into an "S shape." Low energy electrons (<0.3 MeV) are less subject to hiss scattering below L = 4. In contrast, 0.3-1.5 MeV electrons evolve in an environment that depopulates them as they migrate from L 5 to L 2.5. Ultrarelativistic electrons are not affected by hiss losses until L 2-3.

  13. Generation of Nonlinear Electric Field Bursts in the Outer Radiation Belt through Electrons Trapping by Oblique Whistler Waves

    Science.gov (United States)

    Agapitov, Oleksiy; Drake, James; Mozer, Forrest

    2016-04-01

    Huge numbers of different nonlinear structures (double layers, electron holes, non-linear whistlers, etc. referred to as Time Domain Structures - TDS) have been observed by the electric field experiment on board the Van Allen Probes. A large part of the observed non-linear structures are associated with whistler waves and some of them can be directly driven by whistlers. The parameters favorable for the generation of TDS were studied experimentally as well as making use of 2-D particle-in-cell (PIC) simulations for the system with inhomogeneous magnetic field. It is shown that an outward propagating front of whistlers and hot electrons amplifies oblique whistlers which collapse into regions of intense parallel electric field with properties consistent with recent observations of TDS from the Van Allen Probe satellites. Oblique whistlers seed the parallel electric fields that are driven by the beams. The resulting parallel electric fields trap and heat the precipitating electrons. These electrons drive spikes of intense parallel electric field with characteristics similar to the TDSs seen in the VAP data. The decoupling of the whistler wave and the nonlinear electrostatic component is shown in PIC simulation in the inhomogeneous magnetic field system. These effects are observed by the Van Allen Probes in the radiation belts. The precipitating hot electrons propagate away from the source region in intense bunches rather than as a smooth flux.

  14. Nonlinear whistler wave model for lion roars in the Earth's magnetosheath

    Science.gov (United States)

    Dwivedi, N. K.; Singh, S.

    2017-09-01

    In the present study, we construct a nonlinear whistler wave model to explain the magnetic field spectra observed for lion roars in the Earth's magnetosheath region. We use two-fluid theory and semi-analytical approach to derive the dynamical equation of whistler wave propagating along the ambient magnetic field. We examine the magnetic field localization of parallel propagating whistler wave in the intermediate beta plasma applicable to the Earth's magnetosheath. In addition, we investigate spectral features of the magnetic field fluctuations and the spectral slope value. The magnetic field spectrum obtained by semi-analytical approach shows a spectral break point and becomes steeper at higher wave numbers. The observations of IMP 6 plasma waves and magnetometer experiment reveal the existence of short period magnetic field fluctuations in the magnetosheath. The observation shows the broadband spectrum with a spectral slope of -4.5 superimposed with a narrow band peak. The broadband fluctuations appear due to the energy cascades attributed by low-frequency magnetohydrodynamic modes, whereas, a narrow band peak is observed due to the short period lion roars bursts. The energy spectrum predicted by the present theoretical model shows a similar broadband spectrum in the wave number domain with a spectral slope of -3.2, however, it does not show any narrow band peak. Further, we present a comparison between theoretical energy spectrum and the observed spectral slope in the frequency domain. The present semi-analytical model provides exposure to the whistler wave turbulence in the Earth's magnetosheath.

  15. Generation mechanism of the whistler-mode waves in the plasma sheet prior to magnetic reconnection

    Czech Academy of Sciences Publication Activity Database

    Wei, X. H.; Cao, J. B.; Zhou, G. C.; Fu, H. S.; Santolík, Ondřej; Reme, H.; Dandouras, I.; Cornilleau, N.; Fazakerley, A.

    2013-01-01

    Roč. 52, č. 1 (2013), s. 205-210 ISSN 0273-1177 Institutional support: RVO:68378289 Keywords : whistler-mode waves * electron temperature anisotropy * Reconnection * the plasma sheet Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.238, year: 2013 http://www.sciencedirect.com/science/article/pii/S0273117713001221

  16. The epidemiology of mountain bike park injuries at the Whistler Bike Park, British Columbia (BC), Canada.

    Science.gov (United States)

    Ashwell, Zachary; McKay, Mary Pat; Brubacher, Jeffery R; Gareau, Annie

    2012-06-01

    To describe the epidemiology of injuries sustained during the 2009 season at Whistler Mountain Bike Park. A retrospective chart review was performed of injured bike park cyclists presenting to the Whistler Health Clinic between May 16 and October 12, 2009. Of 898 cases, 86% were male (median age, 26 years), 68.7% were Canadian, 19.4% required transport by the Whistler Bike Patrol, and 8.4% arrived by emergency medical services. Identification of 1759 specific injury diagnoses was made, including 420 fractures in 382 patients (42.5%). Upper extremity fractures predominated (75.4%), 11.2% had a traumatic brain injury, and 8.5% were transferred to a higher level of care: 7 by helicopter, 62 by ground, and 5 by personal vehicle. Two patients refused transfer. Mountain bikers incurred many injuries with significant morbidity while riding in the Whistler Mountain Bike Park in 2009. Although exposure information is unavailable, these findings demonstrate serious risks associated with this sport and highlight the need for continued research into appropriate safety equipment and risk avoidance measures. Copyright © 2012 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  17. Ducted whistler-mode signals received at two widely spaced locations

    Directory of Open Access Journals (Sweden)

    M. A. Clilverd

    Full Text Available Whistler-mode signals from a single VLF transmitter that have propagated in the same duct, have been observed simultaneously at Faraday, Antarctica (65°S, 64°W and Dunedin, New Zealand (46°S, 171°E. The signals received have group-delay times that differ in the order of 10 ms, which can be explained by the differences in southern-hemisphere sub-ionospheric propagation time from duct exit region to receiver for the two sites. This difference has been used to determine the location of the duct exit region, with confirmation provided by arrival-bearing information from both sites. The whistler-mode signals typically occur one or two days after geomagnetic activity, with Kpgeq5. The sub-ionospheric-propagation model, LWPC, is used to estimate the whistler-mode power radiated from the duct exit region. These results are then combined with estimated loss values for ionospheric and ducted transmission to investigate the role of wave-particle amplification or absorption. On at least half of the events studied, plasmaspheric amplification of the signals appears to be needed to explain the observed whistler-mode signal strengths.

  18. Resonant and non-resonant whistlers-particle interaction in the radiation belts

    NARCIS (Netherlands)

    E. Camporeale (Enrico)

    2015-01-01

    htmlabstractWe study the wave-particle interactions between lower band chorus whistlers and an anisotropic tenuous population of relativistic electrons. We present the first direct comparison of first-principle Particle-in-Cell (PIC) simulations with a quasi-linear diffusion code. In the PIC

  19. Resonant and non-resonant whistlers-particle interaction in the radiation belts

    NARCIS (Netherlands)

    E. Camporeale (Enrico)

    2014-01-01

    htmlabstractWe study the wave-particle interactions between lower band chorus whistlers and an anisotropic tenuous population of relativistic electrons. We present the first direct comparison of first-principle Particle-in-Cell (PIC) simulations with a quasi-linear diffusion code, in this context.

  20. Propagation of unducted whistlers from their source lightning: a case study

    Czech Academy of Sciences Publication Activity Database

    Santolík, O.; Parrot, M.; Inan, U. S.; Burešová, Dalia; Gurnett, D. A.; Chum, Jaroslav

    2009-01-01

    Roč. 114, - (2009), A03212/1-A03212/11 ISSN 0148-0227 R&D Projects: GA AV ČR IAA301120601 Institutional research plan: CEZ:AV0Z30420517 Keywords : unducted whistler * DEMETER * ray-tracing Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.082, year: 2009

  1. Seasonal and diurnal variation of lightning activity over southern Africa and correlation with European whistler observations

    Directory of Open Access Journals (Sweden)

    A. B. Collier

    2006-03-01

    Full Text Available Lightning Imaging Sensor (LIS data have been analysed to ascertain the statistical pattern of lightning occurrence over southern Africa. The diurnal and seasonal variations are mapped in detail. The highest flash rates (107.2 km-2 y-1 occur close to the equator but maxima are also found over Madagascar (32.1 km-2 y-1 and South Africa (26.4 km-2 y-1. A feature of the statistics is a relatively steady contribution from over the ocean off the east coast of South Africa that appears to be associated with the Agulhas current. Lightning statistics are of intrinsic meteorological interest but they also relate to the occurrence of whistlers in the conjugate region. Whistler observations are made at Tihany, Hungary. Statistics reveal that the period of most frequent whistler occurrence does not correspond to the maximum in lightning activity in the conjugate region but is strongly influenced by ionospheric illumination and other factors. The whistler/flash ratio, R, shows remarkable variations during the year and has a peak that is narrowly confined to February and March.

  2. Upconversion of whistler waves by gyrating ion beams in a plasma

    Indian Academy of Sciences (India)

    derives the low-frequency mode that, along with the side band, grows exponentially with time at the expense of the energy of the pump and the free energy of the gyrating ion beam. In the present paper, we study the non-linear interaction of high-frequency whistler waves with the negative energy beam cyclotron mode.

  3. Upconversion of whistler waves by gyrating ion beams in a plasma

    Indian Academy of Sciences (India)

    A gyrating ion beam, with a ring-shaped distribution in velocity, supports negative energy beam modes near the harmonics of beam gyro-frequency. An investigation of the non-linear interaction of high-frequency whistler waves with the negative energy beam cyclotron mode is made. A non-linear dispersion relation is ...

  4. Ducted whistler-mode signals received at two widely spaced locations

    Directory of Open Access Journals (Sweden)

    M. A. Clilverd

    1996-06-01

    Full Text Available Whistler-mode signals from a single VLF transmitter that have propagated in the same duct, have been observed simultaneously at Faraday, Antarctica (65°S, 64°W and Dunedin, New Zealand (46°S, 171°E. The signals received have group-delay times that differ in the order of 10 ms, which can be explained by the differences in southern-hemisphere sub-ionospheric propagation time from duct exit region to receiver for the two sites. This difference has been used to determine the location of the duct exit region, with confirmation provided by arrival-bearing information from both sites. The whistler-mode signals typically occur one or two days after geomagnetic activity, with Kp\\geq5. The sub-ionospheric-propagation model, LWPC, is used to estimate the whistler-mode power radiated from the duct exit region. These results are then combined with estimated loss values for ionospheric and ducted transmission to investigate the role of wave-particle amplification or absorption. On at least half of the events studied, plasmaspheric amplification of the signals appears to be needed to explain the observed whistler-mode signal strengths.

  5. A case study of lightning, whistlers, and associated ionospheric effects during a substorm particle injection event

    International Nuclear Information System (INIS)

    Rodriguez, J.V.; Inan, U.S.; Li, Y.Q.; Holzworth, R.H.; Smith, A.J.; Orville, R.E.; Rosenberg, T.J.

    1992-01-01

    Simultaneous ground-based observations of narrowband and broadband VLF radio waves and of cloud-to-ground lightning were made at widely spaced locations during the 1987 Wave-Induced Particle Precipitation (WIPP) campaign, conducted from Wallops Island, Virginia. Based on these observations, the first case study has been made of the relationships among located cloud-to-ground (CG) lightning flashes, whistlers, and associated ionospheric effects during a substorm particle injection event. This event took place 2 days after the strongest geomagnetic storm of 1987, during a reintensification in geomagnetic activity that did not affect the high rate of whistlers observed at Faraday Station, Antarctica. At the time of the injection event, several intense nighttime thunderstorms were located over Long Island and the coast of New England, between 400 km northwest and 600 km north of the region geomagnetically conjugate to Faraday. About two thirds of the CG flashes that were detected in these thunderstorms during the hour following the injection event onset were found to be causatively associated with whistlers received at Faraday. During the same period the amplitude of the 24.0-kHz signal from the NAA transmitter in Cutler, Maine, propagating over the thunderstorm centers toward Wallops Island was repeatedly perturbed in a manner characteristic of previously reported VLF signatures of transient and localized ionization enhancements at D region altitudes. Though such enhancements may have been caused by whistler-induced bursts electron precipitation from the magnetosphere, the data in this case are insufficient to establish a clear connection between the NAA amplitude perturbations and the Faraday Station whistlers. In view of the proximity of the NAA great circle path to the storm center, having the lower ionosphere by intense radiation from lightning may also have played a role in the observed VLF perturbations

  6. Generation of lower hybrid and whistler waves by an ion velocity ring distribution

    International Nuclear Information System (INIS)

    Winske, D.; Daughton, W.

    2012-01-01

    Using fully kinetic simulations in two and three spatial dimensions, we consider the generation and nonlinear evolution of lower hybrid waves produced by a cold ion ring velocity distribution in a low beta plasma. We show that the initial development of the instability is very similar in two and three dimensions and not significantly modified by electromagnetic effects, consistent with linear theory. At saturation, the level of electric field fluctuations is a small fraction of the background thermal energy; the electric field and corresponding density fluctuations consist of long, field-aligned striations. Energy extracted from the ring goes primarily into heating the background ions and the electrons at comparable rates. The initial growth and saturation of the magnetic components of the lower hybrid waves are related to the electric field components, consistent with linear theory. As the growing electric field fluctuations saturate, parallel propagating whistler waves develop by the interaction of two lower hybrid waves. At later times, these whistlers are replaced by longer wavelength, parallel propagating whistlers that grow through the decay of the lower hybrid fluctuations. Wave matching conditions demonstrate these conversion processes of lower hybrid waves to whistler waves. The conversion efficiency (=ratio of the whistler wave energy to the energy in the saturated lower hybrid waves) is computed and found to be significant (∼15%) for the parameters of the three-dimensional simulation (and even larger in the two-dimensional simulation), although when normalized in terms of the initial kinetic energy in the ring ions the overall efficiency is very small ( −4 ). The results are compared with relevant linear and nonlinear theory.

  7. Triggering Artefacts

    DEFF Research Database (Denmark)

    Mogensen, Preben Holst; Robinson, Mike

    1995-01-01

    The paper presents a general critique of the use of conceptual frameworks in design, illustrated by the well known synchronous/asynchronous, co-located/non-co-located framework. It argues that while frameworks are a necessary and inevitable starting point for design, the business of tailoring...... and adapting them to specific situations need not be ad hoc.Triggering artefacts are a way of systematically challenging both designers' preunderstandings and the conservatism of work practice. Experiences from the Great Belt tunnel and bridge project are used to illustrate howtriggering artefacts change...

  8. Energy transfer from lower energy to higher-energy electrons mediated by whistler waves in the radiation belts

    Science.gov (United States)

    Shklyar, D. R.

    2017-01-01

    We study the problem of energy exchange between waves and particles, which leads to energization of the latter, in an unstable plasma typical of the radiation belts. The ongoing Van Allen Probes space mission brought this problem among the most discussed in space physics. A free energy which is present in an unstable plasma provides the indispensable condition for energy transfer from lower energy particles to higher-energy particles via resonant wave-particle interaction. This process is studied in detail by the example of electron interactions with whistler mode wave packets originated from lightning-induced emission. We emphasize that in an unstable plasma, the energy source for electron energization is the energy of other particles, rather than the wave energy as is often assumed. The way by which the energy is transferred from lower energy to higher-energy particles includes two processes that operate concurrently, in the same space-time domain, or sequentially, in different space-time domains, in which a given wave packet is located. In the first process, one group of resonant particles gives the energy to the wave. The second process consists in wave absorption by another group of resonant particles, whose energy therefore increases. We argue that this mechanism represents an efficient means of electron energization in the radiation belts.

  9. Refractory black carbon at the Whistler Peak High Elevation Research Site - Measurements and simulations

    Science.gov (United States)

    Hanna, Sarah J.; Xu, Jun-Wei; Schroder, Jason C.; Wang, Qiaoqiao; McMeeking, Gavin R.; Hayden, Katherine; Leaitch, W. Richard; Macdonald, AnneMarie; von Salzen, Knut; Martin, Randall V.; Bertram, Allan K.

    2018-05-01

    Measurements of black carbon at remote and high altitude locations provide an important constraint for models. Here we present six months of refractory black carbon (rBC) data collected in July-August of 2009, June-July of 2010, and April-May of 2012 using a single particle soot photometer (SP2) at the remote Whistler High Elevation Research Site in the Coast Mountains of British Columbia (50.06°N, 122.96°W, 2182 m a.m.s.l). In order to reduce regional boundary layer influences, only measurements collected during the night (2000-0800 PST) were considered. Times impacted by local biomass burning were removed from the data set, as were periods of in-cloud sampling. Back trajectories and back trajectory cluster analysis were used to classify the sampled air masses as Southern Pacific, Northern Pacific, Western Pacific/Asian, or Northern Canadian in origin. The largest rBC mass median diameter (182 nm) was seen for air masses in the Southern Pacific cluster, and the smallest (156 nm) was seen for air masses in the Western Pacific/Asian cluster. Considering all the clusters, the median mass concentration of rBC was 25.0 ± 7.6 ng/m3-STP. The Northern Pacific, Southern Pacific, Western Pacific/Asian, and Northern Canada clusters had median mass concentrations of 25.0 ± 7.6, 21.3 ± 6.9, 25.0 ± 7.9, and 40.6 ± 12.9 ng/m3-STP, respectively. We compared these measurements with simulations from the global chemical transport model GEOS-Chem. The default GEOS-Chem simulations overestimated the median rBC mass concentrations for the different clusters by a factor of 1.2-2.2. The largest difference was observed for the Northern Pacific cluster (factor of 2.2) and the smallest difference was observed for the Northern Canada cluster (factor of 1.2). A sensitivity simulation that excluded Vancouver emissions still overestimated the median rBC mass concentrations for the different clusters by a factor of 1.1-2.0. After implementation of a revised wet scavenging scheme, the

  10. Turbulent cascade in the solar wind at kinetic scales and quasi-parallel whistler waves

    Science.gov (United States)

    Alexandrova, O.; Lacombe, C.; Mangeney, A.; Grappin, R.; Maksimovic, M.; Matteini, L.; Santolik, O.; Cornilleau-Wehrlin, N.; de Conchy, Y.

    2014-12-01

    The nature of the magnetic field fluctuations in the solar wind between the ion and electron scales is still under debate. Using the Cluster/STAFF instrument, we make a survey of the power spectral density and of the polarization of these fluctuations at frequencies 1-400 Hz, during five years (2001-2005) when Cluster was in the free solar wind, i.e. not magnetically connected to the Earth's bow-shock.In most of the analyzed time intervals, the fluctuations are non-polarized and they have a general spectral shape between the ion scales and a fraction of electron scales. The intensity of these spectra is well correlated to the ion thermal pressure. These non-polarized fluctuations seem to have a negligible frequency in the solar wind frame, and a wavevector anisotropy kperp>>k||. In the rest ~10% of the selected data, we observe narrow-band, right-handed, circularly polarized fluctuations, with wave vectors quasi-parallel to the mean magnetic field, superimposed on the spectrum of the permanent background turbulence. We interpret these coherent fluctuations as whistler mode waves. The life time of such waves varies between a few seconds and several hours. We analyze in details the long-lived whistler waves, i.e. with a life time longer than five minutes. We find several conditions for the appearance of such waves: (1) a low level of the background turbulence; (2) a low ion thermal pressure; (3) a slow solar wind speed; (4) an electron heat flux Qe>4μW/m2; (5) an electron mean free path larger than 0.5 AU, i.e., a low collisional frequency; (6) a change in the magnetic field direction. When the level of the background turbulence is high, we cannot affirm that whistler waves do not exist: they can be just masked by the turbulence. The six above conditions for the presence of parallel whistlers in the free solar wind are necessary but are not sufficient. When the electron parallel beta factor βe is larger than 3, the whistler waves are seen along the heat flux

  11. On the interactions between energetic electrons and lightning whistler waves observed at high L-shells on Van Allen Probes

    Science.gov (United States)

    Zheng, H.; Holzworth, R. H., II; Brundell, J. B.; Hospodarsky, G. B.; Jacobson, A. R.; Fennell, J. F.; Li, J.

    2017-12-01

    Lightning produces strong broadband radio waves, called "sferics", which propagate in the Earth-ionosphere waveguide and are detected thousands of kilometers away from their source. Global real-time detection of lightning strokes including their time, location and energy, is conducted with the World Wide Lightning Location Network (WWLLN). In the ionosphere, these sferics couple into very low frequency (VLF) whistler waves which propagate obliquely to the Earth's magnetic field. A good match has previously been shown between WWLLN sferics and Van Allen Probes lightning whistler waves. It is well known that lightning whistler waves can modify the distribution of energetic electrons in the Van Allen belts by pitch angle scattering into the loss cone, especially at low L-Shells (referred to as LEP - Lightning-induced Electron Precipitation). It is an open question whether lightning whistler waves play an important role at high L-shells. The possible interactions between energetic electrons and lightning whistler waves at high L-shells are considered to be weak in the past. However, lightning is copious, and weak pitch angle scattering into the drift or bounce loss cone would have a significant influence on the radiation belt populations. In this work, we will analyze the continuous burst mode EMFISIS data from September 2012 to 2016, to find out lightning whistler waves above L = 3. Based on that, MAGEIS data are used to study the related possible wave-particle interactions. In this talk, both case study and statistical analysis results will be presented.

  12. Ion and relativistic electron acceleration by Alfven and whistler turbulence in solar flares

    Science.gov (United States)

    Miller, James A.; Ramaty, Reuven

    1987-01-01

    A model is proposed in which turbulent Alfven and whistler waves simultaneously produce the proton and electron spectra implied by the gamma-ray observations noted during the impulsive phase of the June 3, 1982 flare. The results demonstrate that protons can be accelerated to several GeV in less than about 10 sec by Alfven turbulence whose energy density is greater than a few erg/cu cm. It is also found that electrons may be accelerated to tens of MeV on similar time scales by whistler and Alfven turbulence. A lower limit on the energy density of the Alfven turbulence is obtained which is small compared to the total magnetic energy density.

  13. Correlated observations of intensified whistler waves and electron acceleration around the geostationary orbit

    International Nuclear Information System (INIS)

    Xiao Fuliang; He Zhaoguo; Tang Lijun; Zong Qiugang; Wang Chengrui; Su Zhenpeng

    2012-01-01

    We report correlated observations of enhanced whistler waves and energetic electron acceleration collected by multiple satellites specifically near the geostationary orbit during the 7–10 November 2004 superstorms, together with multi-site observations of ULF wave power measured on the ground. Energetic (>0.6 MeV) electron fluxes are found to increase significantly during the recovery phase, reaching a peak value by ∼100 higher than the prestorm level. In particular, such high electron flux corresponds to intensified whistler wave activities but to the weak ULF wave power. This result suggests that wave–particle interaction appears to be more important than inward radial diffusion in acceleration of outer radiation belt energetic electrons in this event, assisting to better understand the acceleration mechanism. (paper)

  14. Direction finding of night-time whistlers at very low latitudes in China - Preliminary results

    Science.gov (United States)

    Xu, J. S.; Tian, M.; Tang, C. C.; Hayakawa, M.; Ohta, K.; Shimakura, S.

    1989-09-01

    Simultaneous direction finding measurements of equatorial latitude whistlers have been performed in January 1988 at three stations in China, including Zhanjiang (geomagnetic latitude 10.0 deg N), Guilin (14.1 deg), and Wuchang (19.4 deg). The preliminary analyses for a particular day have shown experimentally that there is a single-valued dispersion value (D = 10.5 sq rt s) for nighttime whistlers at the three stations and that their ionospheric exit region is located just in the zenith of Zhanjiang, with an approximately right-handed circular polarization. This finding lends strong evidence to a previous implication, inferred from the simultaneous multistation network, that there is a preferred propagation channel at a geomagnetic latitude aroung 10 deg.

  15. Constructing a Climatology of Whistler Wave Energy from Lightning in Low Earth Orbit

    Science.gov (United States)

    2011-12-16

    be observed from the ground testifies to the stability of some field aligned ducts. The issue of what fraction of whistler energy is ducted is...this is likely a good approximation. Simple geometry tells us that from an altitude of 100 km the line of sight viewing is approximately cos-1( 6380 ...is ongoing. Acknowledgments. The LIS/OTD HRMC_COM_FR (monthly) and LRADC_COM_SMFR2 climatology data were produced by the LIS/OTD Science Team

  16. Turbulent fluctuations at kinetic scales: from coherent structures to quasi-parallel whistler waves

    Science.gov (United States)

    Alexandrova, Olga; Lacombe, Catherine; Matteini, Lorenzo; Rossi, Claudia; Maksimovic, Milan; Mangeney, Andre; Santolik, Ondrej; Cornilleau-Wehrlin, Nicole; de Conchy, Yvonne

    2015-04-01

    The nature of the magnetic field fluctuations in the solar wind between the ion and electron scales is still under debate. Using the Cluster/STAFF instrument, we make a survey of the power spectral density and of the polarization of these fluctuations at frequencies f ∈ [1,400] Hz, during five years (2001-2005) when Cluster was in the free solar wind. In most of the analyzed time intervals, the fluctuations have quasi-random polarization and they have a general spectral shape between the ion scales and a fraction of electron scales. The intensity of these spectra is well correlated to the ion thermal pressure. These fluctuations seem to have a negligible frequency in the solar wind frame, and a wavevector anisotropy k⊥ ≫ k||. Such time intervals are dominated by coherent structures, propagating with a finit velocity in the plasma frame, in the plane perpendicular to the mean magnetic field. In the rest ~ 10% of the selected data, we observe narrow-band, right-handed, circularly polarized fluctuations, with wave vectors quasi-parallel to the mean magnetic field, superimposed on the spectrum of the permanent background turbulence. We interpret these coherent fluctuations as whistler mode waves. The life time of such waves varies between a few seconds and several hours. We analyze in details the long-lived whistler waves, i.e. with a life time longer than five minutes. When the electron parallel beta factor βe|| is larger than 3, the whistler waves are seen along the heat flux threshold of the whistler heat flux instability.

  17. Nonlinear propagation of whistler wave and turbulent spectrum in reconnection region of magnetopause

    Science.gov (United States)

    Sharma, R. P.; Pathak, Neha; Yadav, Nitin; Sharma, Prachi

    2017-09-01

    Whistler waves have ample of observations in the magnetosphere near the dayside magnetopause. Also, the role of whistler waves is well established in the context of magnetic reconnection as well as turbulence generation. In the present work, we examine the combined effect of guide field and nonlinearity in the development of turbulence in magnetic reconnection sites. We have derived the dynamical equation of 3D whistler wave propagating through Harris sheet assuming that background number density and background field are perturbed. The nonlinear dynamical equation is then solved numerically using pseudo-spectral method and finite difference method. Simulation results represent the nonlinear evolution of X-O field line in the presence of nonlinearity, which causes the generation of turbulence. We have also investigated the formation of current sheet/coherent structures as a result of the proposed mechanism. These localized structures have transverse scale size of the order of electron inertial length. When the system reaches quasi steady state, we have evaluated power spectrum in magnetopause and it shows two different scaling having k-3 /2 for k λe1 .The obtained results are consistent with the THEMIS observations. Energy distribution at smaller scales leads to the formation of thermal tail of energetic particles. The energy of these electrons is also calculated and comes out to be in the order of 100 keV.

  18. Effect of Guide Field in Localization of Whistler Wave and Turbulent Spectrum in Magnetic Reconnection Sites

    Science.gov (United States)

    Pathak, N.; Sharma, R. P.; Uma, R.

    2017-12-01

    Whistler waves have ample of observations in the magnetosphere near the dayside magnetopause. Also, the role of whistler waves is well established in the context of magnetic reconnection as well as turbulence generation. In the present work, we examine the combined effect of guide field and nonlinearity in the development of turbulence in magnetic reconnection sites. We have derived the dynamical equation of 3D whistler wave propagating through Harris sheet assuming that background number density and background field are perturbed. The nonlinear dynamical equation is then solved numerically using pseudo spectral method and finite difference method. Simulation results represent the nonlinear evolution of X-O field line in the presence of nonlinearity, which causes the generation of turbulence. When the system reaches quasi steady state, we have evaluated power spectrum in magnetopause and it shows two different scaling having k-3/2 at larger saclesand k-3 at smaller scales. Energy distribution at smaller scales leads to the formation of thermal tail of energetic particles. The energy of these electrons is also calculated and comes out to be in the order of 100 keV.

  19. Generation of Electron Whistler Waves at the Mirror Mode Magnetic Holes: MMS Observations and PIC Simulation

    Science.gov (United States)

    Ahmadi, N.; Wilder, F. D.; Usanova, M.; Ergun, R.; Argall, M. R.; Goodrich, K.; Eriksson, S.; Germaschewski, K.; Torbert, R. B.; Lindqvist, P. A.; Le Contel, O.; Khotyaintsev, Y. V.; Strangeway, R. J.; Schwartz, S. J.; Giles, B. L.; Burch, J.

    2017-12-01

    The Magnetospheric Multiscale (MMS) mission observed electron whistler waves at the center and at the gradients of magnetic holes on the dayside magnetosheath. The magnetic holes are nonlinear mirror structures which are anti-correlated with particle density. We used expanding box Particle-in-cell simulations and produced the mirror instability magnetic holes. We show that the electron whistler waves can be generated at the gradients and the center of magnetic holes in our simulations which is in agreement with MMS observations. At the nonlinear regime of mirror instability, the proton and electron temperature anisotropy are anti-correlated with the magnetic hole. The plasma is unstable to electron whistler waves at the minimum of the magnetic field structures. In the saturation regime of mirror instability, when magnetic holes are dominant, electron temperature anisotropy develops at the edges of the magnetic holes and electrons become isotropic at the magnetic field minimum. We investigate the possible mechanism for enhancing the electron temperature anisotropy and analyze the electron pitch angle distributions and electron distribution functions in our simulations and compare it with MMS observations.

  20. Energy dissipation by whistler turbulence: Three-dimensional particle-in-cell simulations

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ouliang, E-mail: ouliang@usc.edu [Oracle Corporation, Redwood City, California 94065 (United States); Peter Gary, S., E-mail: pgary@lanl.gov [Space Science Institute, Boulder, Colorado (United States); Wang, Joseph, E-mail: josephjw@usc.edu [University of Southern California, Los Angeles, California (United States)

    2014-05-15

    Three-dimensional particle-in-cell simulations of whistler turbulence are carried out on a collisionless, homogeneous, magnetized plasma model. The simulations use an initial ensemble of relatively long wavelength whistler modes and follow the temporal evolution of the fluctuations as they cascade into a broadband, anisotropic, turbulent spectrum at shorter wavelengths. For relatively small levels of the initial fluctuation energy ϵ{sub e}, linear collisionless damping provides most of the dissipation of the turbulence. But as ϵ{sub e} and the total dissipation increase, linear damping becomes less important and, especially at β{sub e} ≪ 1, nonlinear processes become stronger. The PDFs and kurtoses of the magnetic field increments in the simulations suggest that intermittency in whistler turbulence generally increases with increasing ϵ{sub e} and β{sub e}. Correlation coefficient calculations imply that the current structure dissipation also increases with increasing ϵ{sub e} and β{sub e}, and that the nonlinear dissipation processes in these simulations are primarily associated with regions of localized current structures.

  1. Energy dissipation by whistler turbulence: Three-dimensional particle-in-cell simulations

    International Nuclear Information System (INIS)

    Chang, Ouliang; Peter Gary, S.; Wang, Joseph

    2014-01-01

    Three-dimensional particle-in-cell simulations of whistler turbulence are carried out on a collisionless, homogeneous, magnetized plasma model. The simulations use an initial ensemble of relatively long wavelength whistler modes and follow the temporal evolution of the fluctuations as they cascade into a broadband, anisotropic, turbulent spectrum at shorter wavelengths. For relatively small levels of the initial fluctuation energy ϵ e , linear collisionless damping provides most of the dissipation of the turbulence. But as ϵ e and the total dissipation increase, linear damping becomes less important and, especially at β e ≪ 1, nonlinear processes become stronger. The PDFs and kurtoses of the magnetic field increments in the simulations suggest that intermittency in whistler turbulence generally increases with increasing ϵ e and β e . Correlation coefficient calculations imply that the current structure dissipation also increases with increasing ϵ e and β e , and that the nonlinear dissipation processes in these simulations are primarily associated with regions of localized current structures

  2. Parametric excitation of very low frequency (VLF) electromagnetic whistler waves and interaction with energetic electrons in radiation belt

    Science.gov (United States)

    Sotnikov, V.; Kim, T.; Caplinger, J.; Main, D.; Mishin, E.; Gershenzon, N.; Genoni, T.; Paraschiv, I.; Rose, D.

    2018-04-01

    The concept of a parametric antenna in ionospheric plasma is analyzed. Such antennas are capable of exciting electromagnetic radiation fields, specifically the creation of whistler waves generated at the very low frequency (VLF) range, which are also capable of propagating large distances away from the source region. The mechanism of whistler wave generation is considered a parametric interaction of quasi-electrostatic whistler waves (also known as low oblique resonance (LOR) oscillations) excited by a conventional loop antenna. The interaction of LOR waves with quasi-neutral density perturbations in the near field of an antenna gives rise to electromagnetic whistler waves on combination frequencies. It is shown in this work that the amplitude of these waves can considerably exceed the amplitude of whistler waves directly excited by a loop. Additionally, particle-in-cell simulations, which demonstrate the excitation and spatial structure of VLF waves excited by a loop antenna, are presented. Possible applications including the wave-particle interactions to mitigate performance anomalies of low Earth orbit satellites, active space experiments, communication via VLF waves, and modification experiments in the ionosphere will be discussed.

  3. Ducting of the Whistler-Mode Waves by Magnetic Field-Aligned Density Enhancements in the Radiation Belt

    Science.gov (United States)

    Streltsov, A. V.; Bengtson, M.; English, D.; Miller, M.; Turco, L.

    2017-12-01

    Whistler-mode waves (or whistlers) are the right-hand polarized electromagnetic waves with a frequency in the range above the lower hybrid frequency and below the electron cyclotron frequency. They can efficiently interact with energetic electrons in the equatorial magnetosphere and remediate them from the earth's radiation belt. These interactions are non-linear, they depend on the wave amplitude, and for them to be efficient the wave power needs to be delivered from the transmitter to the interaction region without significant losses. The main physical mechanism which can solve this problem is ducting/guiding of whistlers by magnetic field-aligned density inhomogeneities or ducts. We present results from a modeling of whistler-mode waves observed by the NASA Van Allen Probes satellites inside the ducts formed by density enhancements (also known as, high-density ducts or HDD). Our previous studies suggest that HDD can confine without leakage only waves with some particular parameters (frequency, perpendicular and parallel wavelength) connected with the parameters of the duct (like duct's "width" and "depth"). Our numerical results confirm that 1) the high-density ducts with amplitudes and perpendicular sizes observed by the RBSP satellites can indeed guide whistlers over significant distances along the ambient magnetic field with small leakage, and 2) the quality of the ducting indeed depends on the wave perpendicular and parallel wavelengths and, therefore, the fact that the wave is ducted by HDD can be used to determine parameters of the wave.

  4. On the dispersion law of low-frequency electron whistler waves in a multi-ion plasma

    Directory of Open Access Journals (Sweden)

    B. V. Lundin

    2008-06-01

    Full Text Available A new and simple dispersion law for extra-low-frequency electron whistler waves in a multi-ion plasma is derived. It is valid in a plasma with finite ratio ωc/ωpe of electron gyro-to-plasma frequency and is suitable for wave frequencies much less than ωpe but well above the gyrofrequencies of most heavy ions. The resultant contribution of the ions to the dispersion law is expressed by means of the lower hybrid resonance frequency, the highest ion cutoff frequency and the relative content of the lightest ion. In a frequency domain well above the ions' gyrofrequencies, this new dispersion law merges with the "modified electron whistler dispersion law" determined in previous works by the authors. It is shown that it fits well to the total cold plasma electron whistler dispersion law, for different orientations of the wave vectors and different ion constituents, including negative ions or negatively charged dust grains.

  5. Whistler wave propagation in the antenna near and far fields in the Naval Research Laboratory Space Physics Simulation Chamber

    International Nuclear Information System (INIS)

    Blackwell, David D.; Walker, David N.; Amatucci, William E.

    2010-01-01

    In previous papers, early whistler propagation measurements were presented [W. E. Amatucci et al., IEEE Trans. Plasma Sci. 33, 637 (2005)] as well as antenna impedance measurements [D. D. Blackwell et al., Phys. Plasmas 14, 092106 (2007)] performed in the Naval Research Laboratory Space Physics Simulation Chamber (SPSC). Since that time there have been major upgrades in the experimental capabilities of the laboratory in the form of improvement of both the plasma source and antennas. This has allowed access to plasma parameter space that was previously unattainable, and has resulted in measurements that provide a significantly clearer picture of whistler propagation in the laboratory environment. This paper presents some of the first whistler experimental results from the upgraded SPSC. Whereas previously measurements were limited to measuring the cyclotron resonance cutoff and elliptical polarization indicative of the whistler mode, now it is possible to experimentally plot the dispersion relation itself. The waves are driven and detected using balanced dipole and loop antennas connected to a network analyzer, which measures the amplitude and phase of the wave in two dimensions (r and z). In addition the frequency of the signals is also swept over a range of several hundreds of megahertz, providing a comprehensive picture of the near and far field antenna radiation patterns over a variety of plasma conditions. The magnetic field is varied from a few gauss to 200 G, with the density variable over at least 3 decades from 10 7 to 10 10 cm -3 . The waves are shown to lie on the dispersion surface for whistler waves, with observation of resonance cones in agreement with theoretical predictions. The waves are also observed to propagate without loss of amplitude at higher power, a result in agreement with previous experiments and the notion of ducted whistlers.

  6. Precipitation of trapped relativistic electrons by amplified whistler waves in the magnetosphere

    International Nuclear Information System (INIS)

    Kuo, S. P.; Kuo, Steven S.; Huynh, James T.; Kossey, Paul

    2007-01-01

    Numerical study of a loss-cone negative mass instability to amplify whistler waves by energetic electrons in the radiation belts is presented. The results show that a very low intensity whistler wave can be amplified by 50 keV electrons more than 25 dB, consistent with the Siple experimental result [Helliwell et al., J. Geophys. Res. 85, 3360 (1980)]. The dependencies of the amplification factor on the energetic electron density and on the initial wave intensity are evaluated. It is shown that the amplification factor decreases as the initial wave intensity increases. However, this gain can still exceed 15 dB for a 30 dB increase of the initial wave intensity, which is needed for the purpose of precipitating MeV electrons in the radiation belts. We then show that there exists a double resonance situation, by which, as an example, a wave is simultaneously in cyclotron resonance with 50 keV electrons as well as with 1.5 MeV electrons; the wave is first amplified by 50 keV electrons and then precipitates 1.5 MeV electrons. With the aid of the cyclotron resonance, the threshold field for the commencement of chaos in the electron trajectories is reduced considerably from that for a general case. Pitch angle scattering of 1.5 MeV electrons is demonstrated. The results show that a whistler wave with magnetic field amplitude of 0.08% of the background magnetic field can scatter electrons from an initial pitch angle of 86.5 deg. to a pitch angle <50 deg

  7. Evidence for acceleration of outer zone electrons to relativistic energies by whistler mode chorus

    Directory of Open Access Journals (Sweden)

    N. P. Meredith

    2002-07-01

    Full Text Available We use plasma wave and electron data from the Combined Release and Radiation Effects Satellite (CRRES to investigate the viability of a local stochastic electron acceleration mechanism to relativistic energies driven by gyroresonant interactions with whistler mode chorus. In particular, we examine the temporal evolution of the spectral response of the electrons and the waves during the 9 October 1990 geomagnetic storm. The observed hardening of the electron energy spectra over about 3 days in the recovery phase is coincident with prolonged substorm activity, as monitored by the AE index and enhanced levels of whistler mode chorus waves. The observed spectral hardening is observed to take place over a range of energies appropriate to the resonant energies associated with Doppler-shifted cyclotron resonance, as supported by the construction of realistic resonance curves and resonant diffusion surfaces. Furthermore, we show that the observed spectral hardening is not consistent with energy-independent radial diffusion models. These results provide strong circumstantial evidence for a local stochastic acceleration mechanism, involving the energisation of a seed population of electrons with energies of the order of a few hundred keV to relativistic energies, driven by wave-particle interactions involving whistler mode chorus. The results suggest that this mechanism contributes to the reformation of the relativistic outer zone population during geomagnetic storms, and is most effective when the recovery phase is characterised by prolonged substorm activity. An additional significant result of this paper is that we demonstrate that the lower energy part of the storm-time electron distribution is in steady-state balance, in accordance with the Kennel and Petschek (1966 theory of limited stably-trapped particle fluxes.Key words. Magnetospheric physics (storms and substorms, energetic particles, trapped – Space plasma physics (wave-particle interactions

  8. James McNeill Whistler: entre o mercado e a defesa da Arte

    OpenAIRE

    Camila Zanon Paglione

    2014-01-01

    A fim de observar o impacto de uma ideologia sobre a conduta e a realidade material de um artista, a pesquisa analisou o livro publicado em 1892 pelo americano James McNeill Whistler, The Gentle Art of Making Enemies. Posicionando-se diante dos paradoxos impostos pela autonomia da Arte, o pintor elaborou uma série de estratégias que visavam garantir uma imagem pública definida dentro dos parâmetros esperados para um artista livre, baseando-se principalmente no uso da imprensa para divulgação ...

  9. Long-wavelength instability of periodic flows and whistler waves in electron magnetohydrodynamics

    International Nuclear Information System (INIS)

    Lakhin, V.P.; Levchenko, V.D.

    2003-01-01

    Stability analysis of periodic flows and whistlers with respect to long-wavelength perturbations within the framework of dissipative electron magnetohydrodynamics (EMHD) based on two-scale asymptotic expansion technique is presented. Several types of flows are considered: two-dimensional Kolmogorov-like flow, helical flow, and anisotropic helical flow. It is shown hat the destabilizing effect on the long-wavelength perturbations is due to either the negative resistivity effect related to flow anisotropy or α-like effect to its micro helicity. The criteria of the corresponding instabilities are obtained. Numerical simulations of EMHD equations with the initial conditions corresponding to two types of periodic flows are presented. (author)

  10. Different types of whistler mode chorus in the equatorial source region

    Czech Academy of Sciences Publication Activity Database

    Taubenschuss, Ulrich; Santolík, Ondřej; Graham, D. B.; Fu, H.; Khotyaintsev, Y. V.; Le Contel, O.

    2015-01-01

    Roč. 42, č. 20 (2015), s. 8271-8279 ISSN 0094-8276 R&D Projects: GA ČR(CZ) GAP209/11/2280; GA MŠk LH12231 Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : whistler mode * chorus * equatorial source * wave normals * Gendrin angle * spectral gap Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.212, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/2015GL066004/abstract

  11. The LHCb trigger

    International Nuclear Information System (INIS)

    Korolko, I.

    1998-01-01

    This paper describes progress in the development of the LHCb trigger system since the letter of intent. The trigger philosophy has significantly changed, resulting in an increase of trigger efficiency for signal B events. It is proposed to implement a level-1 vertex topology trigger in specialised hardware. (orig.)

  12. Whistler Waves With Electron Temperature Anisotropy And Non-Maxwellian Distribution Functions

    Science.gov (United States)

    Masood, W.

    2017-12-01

    Low frequency waves (˜ 100Hz), popularly known as Lion roars, are ubiquitously observed by satellites in terrestrial magnetosheath. By dint of both wave and electron data from the Cluster spacecraft and employing the linear kinetic theory for the electromagnetic waves, Masood et. al. (Ann. Geophysicae. 24, 1725-1735 (2006)) examined the conjecture made by Thorne and Tsurutani (Nature, 93, 384 (1981)) that whistler waves with electron temperature anisotropy are the progenitors of lion roars. It turned out that the study based upon the bi-Maxwellian distribution function did not come up with a satisfactory explanation of certain disagreements between theory and data. In this paper, we revisit the problem using the generalized (r, q) distribution to carry out the linear stability analysis. It is shown that good qualitative and quantitative agreements are found between theory and data using this distribution. Whistler waves with electron temperature anisotropy are also investigated with other non-Maxwellian distribution functions and general comparison is made in the end and differences in each case are highlighted. The possible applications in space plasmas are also pointed out.

  13. Parametric validations of analytical lifetime estimates for radiation belt electron diffusion by whistler waves

    Directory of Open Access Journals (Sweden)

    A. V. Artemyev

    2013-04-01

    Full Text Available The lifetimes of electrons trapped in Earth's radiation belts can be calculated from quasi-linear pitch-angle diffusion by whistler-mode waves, provided that their frequency spectrum is broad enough and/or their average amplitude is not too large. Extensive comparisons between improved analytical lifetime estimates and full numerical calculations have been performed in a broad parameter range representative of a large part of the magnetosphere from L ~ 2 to 6. The effects of observed very oblique whistler waves are taken into account in both numerical and analytical calculations. Analytical lifetimes (and pitch-angle diffusion coefficients are found to be in good agreement with full numerical calculations based on CRRES and Cluster hiss and lightning-generated wave measurements inside the plasmasphere and Cluster lower-band chorus waves measurements in the outer belt for electron energies ranging from 100 keV to 5 MeV. Comparisons with lifetimes recently obtained from electron flux measurements on SAMPEX, SCATHA, SAC-C and DEMETER also show reasonable agreement.

  14. Myofascial trigger point pain.

    Science.gov (United States)

    Jaeger, Bernadette

    2013-01-01

    Myofascial trigger point pain is an extremely prevalent cause of persistent pain disorders in all parts of the body, not just the head, neck, and face. Features include deep aching pain in any structure, referred from focally tender points in taut bands of skeletal muscle (the trigger points). Diagnosis depends on accurate palpation with 2-4 kg/cm2 of pressure for 10 to 20 seconds over the suspected trigger point to allow the referred pain pattern to develop. In the head and neck region, cervical muscle trigger points (key trigger points) often incite and perpetuate trigger points (satellite trigger points) and referred pain from masticatory muscles. Management requires identification and control of as many perpetuating factors as possible (posture, body mechanics, psychological stress or depression, poor sleep or nutrition). Trigger point therapies such as spray and stretch or trigger point injections are best used as adjunctive therapy.

  15. The Central Trigger Processor (CTP)

    CERN Multimedia

    Franchini, Matteo

    2016-01-01

    The Central Trigger Processor (CTP) receives trigger information from the calorimeter and muon trigger processors, as well as from other sources of trigger. It makes the Level-1 decision (L1A) based on a trigger menu.

  16. Electrostatic lower hybrid waves excited by electromagnetic whistler mode waves scattering from planar magnetic-field-aligned plasma density irregularities

    International Nuclear Information System (INIS)

    Bell, T.F.; Ngo, H.D.

    1990-01-01

    Recent satellite observations demonstrate that high amplitude, short wavelength (5 m ≤ λ ≤ 100 m) electrostatic waves are commonly excited by electromagnetic whistler mode waves propagating in regions of the magnetosphere and topside ionosphere where small-scale magnetic-field-aligned plasma density irregularities are thought to exist. A new theoretical model of this phenomenon is presented, based upon passive linear scattering in a cold magnetoplasma. In this model the electrostatic waves are excited by linear mode coupling as the incident electromagnetic whistler mode waves scatter from the magnetic-field-aligned plasma density irregularities. The excited short wavelength waves are quasi-electrostatic whistler mode waves, a type of lower hybrid wave, whose wave normal lies near the whistler mode resonance cone where the wave refractive index becomes very large. The amplitude of the excited electrostatic lower hybrid waves is calculated for a wide range of values of input electromagnetic wave frequency, wave normal direction, electron plasma frequency, gyrofrequency, ion composition, and irregularity scale and density enhancement. Results indicate that high amplitude lower hybrid waves can be excited over a wide range of parameters for irregularity density enhancements as low as 5% whenever the scale of the irregularity is of the same order as the lower hybrid wavelength

  17. Highlights from the 17th International Conference on Multi-Criteria Decision Making, Whistler, BC, August 6-11, 2004

    Science.gov (United States)

    2005-04-01

    i 1. Introduction ... Introduction The 17th annual conference on Multi-Criteria Decision Making was held at the Whistler Conference Centre from August 6 to 11, 2004. There...Objective Linear Programming (MOLP) algorithms; 5. Industrial engineering applications; 6. Behavioural considerations, and 7. Fuzzy MCDM . 3

  18. Nonlinear competition between the whistler and Alfven firehoses. Journal of Geophysical Research, 106, 13,215, 2001

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Matsumoto, H.

    2001-01-01

    Roč. 106, - (2001), s. 13,215-13,224 ISSN 0148-0227 R&D Projects: GA AV ČR IAB3042106 Institutional research plan: CEZ:AV0Z3042911 Keywords : instability * whistler * Alfven wave Subject RIV: BE - Theoretical Physics Impact factor: 2.609, year: 2001

  19. Common Asthma Triggers

    Science.gov (United States)

    ... Grass Other Triggers If you have asthma, an asthma attack can happen when you are exposed to “asthma ... a second person. Secondhand smoke can trigger an asthma attack. If you have asthma, people should never smoke ...

  20. The KLOE trigger system

    International Nuclear Information System (INIS)

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

    2001-01-01

    A double-level trigger system has been developed for the KLOE experiment. Custom electronics asserts a trigger in a 2 μs decision time. The decision is based on the combined information of the electromagnetic calorimeter and the drift chamber. The entire trigger system is continuously monitored, and data flowing from the trigger system have allowed both an efficient online monitoring of the detector and an online luminosity measurement

  1. Statistical analysis of monochromatic whistler waves near the Moon detected by Kaguya

    Directory of Open Access Journals (Sweden)

    Y. Tsugawa

    2011-05-01

    Full Text Available Observations are presented of monochromatic whistler waves near the Moon detected by the Lunar Magnetometer (LMAG on board Kaguya. The waves were observed as narrowband magnetic fluctuations with frequencies close to 1 Hz, and were mostly left-hand polarized in the spacecraft frame. We performed a statistical analysis of the waves to identify the distributions of their intensity and occurrence. The results indicate that the waves were generated by the solar wind interaction with lunar crustal magnetic anomalies. The conditions for observation of the waves strongly depend on the solar zenith angle (SZA, and a high occurrence rate is recognized in the region of SZA between 40° to 90° with remarkable north-south and dawn-dusk asymmetries. We suggest that ion beams reflected by the lunar magnetic anomalies are a possible source of the waves.

  2. Rapid flattening of butterfly pitch angle distributions of radiation belt electrons by whistler-mode chorus

    International Nuclear Information System (INIS)

    Yang, Chang; Changsha University of Science and Technology, Changsha; Su, Zhenpeng; Xiao, Fuliang; Zheng, Huinan

    2016-01-01

    Van Allen radiation belt electrons exhibit complex dynamics during geomagnetically active periods. Investigation of electron pitch angle distributions (PADs) can provide important information on the dominant physical mechanisms controlling radiation belt behaviors. In this paper, we report a storm time radiation belt event where energetic electron PADs changed from butterfly distributions to normal or flattop distributions within several hours. Van Allen Probes observations showed that the flattening of butterfly PADs was closely related to the occurrence of whistler-mode chorus waves. Two-dimensional quasi-linear STEERB simulations demonstrate that the observed chorus can resonantly accelerate the near-equatorially trapped electrons and rapidly flatten the corresponding electron butterfly PADs. Finally, these results provide a new insight on how chorus waves affect the dynamic evolution of radiation belt electrons.

  3. Very Oblique Whistler Mode Propagation in the Radiation Belts: Effects of Hot Plasma and Landau Damping

    Science.gov (United States)

    Ma, Q.; Artemyev, A. V.; Mourenas, D.; Li, W.; Thorne, R. M.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Reeves, G. D.; Spence, H. E.; Wygant, J.

    2017-12-01

    Satellite observations of a significant population of very oblique chorus waves in the outer radiation belt have fueled considerable interest in the effects of these waves on energetic electron scattering and acceleration. However, corresponding diffusion rates are extremely sensitive to the refractive index N, controlled by hot plasma effects including Landau damping and wave dispersion modifications by suprathermal (15-100 eV) electrons. A combined investigation of wave and electron distribution characteristics obtained from the Van Allen Probes shows that peculiarities of the measured electron distribution significantly reduce Landau damping, allowing wave propagation with high N ˜ 100-200. Further comparing measured refractive indexes with theoretical estimates incorporating hot plasma corrections to the wave dispersion, we provide the first experimental demonstration that suprathermal electrons indeed control the upper limit of the refractive index of highly oblique whistler mode waves. Such results further support the importance of incorporating very oblique waves into radiation belt models.

  4. Whistlers, Helicons, Lower Hybrid Waves: the Physics of RF Wave Absorption Without Cyclotron Resonances

    Science.gov (United States)

    Pinsker, R. I.

    2014-10-01

    In hot magnetized plasmas, two types of linear collisionless absorption processes are used to heat and drive noninductive current: absorption at ion or electron cyclotron resonances and their harmonics, and absorption by Landau damping and the transit-time-magnetic-pumping (TTMP) interactions. This tutorial discusses the latter process, i.e., parallel interactions between rf waves and electrons in which cyclotron resonance is not involved. Electron damping by the parallel interactions can be important in the ICRF, particularly in the higher harmonic region where competing ion cyclotron damping is weak, as well as in the Lower Hybrid Range of Frequencies (LHRF), which is in the neighborhood of the geometric mean of the ion and electron cyclotron frequencies. On the other hand, absorption by parallel processes is not significant in conventional ECRF schemes. Parallel interactions are especially important for the realization of high current drive efficiency with rf waves, and an application of particular recent interest is current drive with the whistler or helicon wave at high to very high (i.e., the LHRF) ion cyclotron harmonics. The scaling of absorption by parallel interactions with wave frequency is examined and the advantages and disadvantages of fast (helicons/whistlers) and slow (lower hybrid) waves in the LHRF in the context of reactor-grade tokamak plasmas are compared. In this frequency range, both wave modes can propagate in a significant fraction of the discharge volume; the ways in which the two waves can interact with each other are considered. The use of parallel interactions to heat and drive current in practice will be illustrated with examples from past experiments; also looking forward, this tutorial will provide an overview of potential applications in tokamak reactors. Supported by the US Department of Energy under DE-FC02-04ER54698.

  5. A global model of thunderstorm electricity and the prediction of whistler duct formation

    International Nuclear Information System (INIS)

    Stansbery, E.K.

    1989-01-01

    A two-dimensional numerical model is created to calculate the electric field and current that flow from a thunderstorm source into the global electrical circuit. The model includes a hemisphere in which the thunderstorm is located, an equalization layer, and a passive magnetic conjugate hemisphere. To maintain the fair weather electric field, the output current from the thunderstorm is allowed to spread out in the ionosphere or flow along the magnetic field lines into the conjugate hemisphere. The vertical current is constant up to approximately 65 km, decays and is redirected horizontally in the ionosphere. Approximately half of the current that reaches the ionosphere flows along magnetic field lines into the conjugate hemisphere while the rest is spread out in the ionosphere and redirected to the fair weather portion of the storm hemisphere. Our results show that it is important to include a realistic model of the equalization layer to evaluate the role of thunderstorm charging of the global circuit. The mapping of thunderstorm electric fields at middle and subauroral latitudes into the magnetic equatorial plane is studied. The geomagnetic field lines are assumed to be dipolar above approximately 150 km. The horizontal electric field computed in the ionosphere by our model is of sufficient size and shape for the formation of electron density irregularities in the magnetosphere. The mechanism involves a localized convection of ionization tubes by ExB drift. It is shown that the horizontal range of the electric field disturbance in the ionosphere must be within approximately 160 km to produce density irregularities necessary for the formation of whistler ducts. Although the electric field strength at ionospheric heights depends sensitively on the conductivity profile, the results presented show that whistler duct formation is possible by thunderstorm generated electric fields.*

  6. Laser-triggered vacuum switch

    Science.gov (United States)

    Brannon, Paul J.; Cowgill, Donald F.

    1990-01-01

    A laser-triggered vacuum switch has a material such as a alkali metal halide on the cathode electrode for thermally activated field emission of electrons and ions upon interaction with a laser beam, the material being in contact with the cathode with a surface facing the discharge gap. The material is preferably a mixture of KCl and Ti powders. The laser may either shine directly on the material, preferably through a hole in the anode, or be directed to the material over a fiber optic cable.

  7. On the dispersion law of low-frequency electron whistler waves in a multi-ion plasma

    Directory of Open Access Journals (Sweden)

    B. V. Lundin

    2008-06-01

    Full Text Available A new and simple dispersion law for extra-low-frequency electron whistler waves in a multi-ion plasma is derived. It is valid in a plasma with finite ratio ωcpe of electron gyro-to-plasma frequency and is suitable for wave frequencies much less than ωpe but well above the gyrofrequencies of most heavy ions. The resultant contribution of the ions to the dispersion law is expressed by means of the lower hybrid resonance frequency, the highest ion cutoff frequency and the relative content of the lightest ion. In a frequency domain well above the ions' gyrofrequencies, this new dispersion law merges with the "modified electron whistler dispersion law" determined in previous works by the authors. It is shown that it fits well to the total cold plasma electron whistler dispersion law, for different orientations of the wave vectors and different ion constituents, including negative ions or negatively charged dust grains.

  8. Trigger Finger (Stenosing Tenosynovitis)

    Science.gov (United States)

    ... a friend * required fields From * To * DESCRIPTION Stenosing tenosynovitis is a condition commonly known as “trigger finger.” It is sometimes also called “trigger thumb.” The tendons that bend the fingers glide easily with ...

  9. Causality and headache triggers

    Science.gov (United States)

    Turner, Dana P.; Smitherman, Todd A.; Martin, Vincent T.; Penzien, Donald B.; Houle, Timothy T.

    2013-01-01

    Objective The objective of this study was to explore the conditions necessary to assign causal status to headache triggers. Background The term “headache trigger” is commonly used to label any stimulus that is assumed to cause headaches. However, the assumptions required for determining if a given stimulus in fact has a causal-type relationship in eliciting headaches have not been explicated. Methods A synthesis and application of Rubin’s Causal Model is applied to the context of headache causes. From this application the conditions necessary to infer that one event (trigger) causes another (headache) are outlined using basic assumptions and examples from relevant literature. Results Although many conditions must be satisfied for a causal attribution, three basic assumptions are identified for determining causality in headache triggers: 1) constancy of the sufferer; 2) constancy of the trigger effect; and 3) constancy of the trigger presentation. A valid evaluation of a potential trigger’s effect can only be undertaken once these three basic assumptions are satisfied during formal or informal studies of headache triggers. Conclusions Evaluating these assumptions is extremely difficult or infeasible in clinical practice, and satisfying them during natural experimentation is unlikely. Researchers, practitioners, and headache sufferers are encouraged to avoid natural experimentation to determine the causal effects of headache triggers. Instead, formal experimental designs or retrospective diary studies using advanced statistical modeling techniques provide the best approaches to satisfy the required assumptions and inform causal statements about headache triggers. PMID:23534872

  10. Triggering the GRANDE array

    International Nuclear Information System (INIS)

    Wilson, C.L.; Bratton, C.B.; Gurr, J.; Kropp, W.; Nelson, M.; Sobel, H.; Svoboda, R.; Yodh, G.; Burnett, T.; Chaloupka, V.; Wilkes, R.J.; Cherry, M.; Ellison, S.B.; Guzik, T.G.; Wefel, J.; Gaidos, J.; Loeffler, F.; Sembroski, G.; Goodman, J.; Haines, T.J.; Kielczewska, D.; Lane, C.; Steinberg, R.; Lieber, M.; Nagle, D.; Potter, M.; Tripp, R.

    1990-01-01

    A brief description of the Gamma Ray And Neutrino Detector Experiment (GRANDE) is presented. The detector elements and electronics are described. The trigger logic for the array is then examined. The triggers for the Gamma Ray and the Neutrino portions of the array are treated separately. (orig.)

  11. Triggering trigeminal neuralgia

    DEFF Research Database (Denmark)

    Di Stefano, Giulia; Maarbjerg, Stine; Nurmikko, Turo

    2018-01-01

    Introduction Although it is widely accepted that facial pain paroxysms triggered by innocuous stimuli constitute a hallmark sign of trigeminal neuralgia, very few studies to date have systematically investigated the role of the triggers involved. In the recently published diagnostic classification...

  12. Terms and conditions for Diesel Emissions Reduction Act Smartway financing projects where an eligible nonprofit grantee is implementing a loan program and loan Recipients will use the loan funds for activities that trigger Davis Bacon

    Science.gov (United States)

    Use this T&C for DERA Smartway financing projects where an eligible nonprofit grantee is implementing a loan program and loan Recipients will use the loan funds for activities that trigger Davis Bacon.

  13. Electron cyclotron emission diagnostics for mirror devices (invited)

    International Nuclear Information System (INIS)

    Ellis, R.F.; James, R.A.; Lasnier, C.J.; Casper, T.

    1985-01-01

    Electron cyclotron emission (ECE) has proven to be a useful diagnostic in tokamaks for measuring T/sub e/ and its radial variation. The application of ECE to mirror devices is discussed here, with emphasis on measurements of the properties of energetic electrons in tandem mirror end cells, which can be viewed both parallel and perpendicular to B. The parallel or whistler view is generally optically thick and can yield a measurement of perpendicular temperature. High harmonic perpendicular emission is optically thin and can yield important information about the hot electron buildup and the energy and spatial distribution. Experimental results from TMX-U and appropriate modeling are presented

  14. ELF whistler events with a reduced intensity observed by the DEMETER spacecraft

    Science.gov (United States)

    Zahlava, J.; Nemec, F.; Santolik, O.; Kolmasova, I.; Parrot, M.

    2017-12-01

    A survey of VLF frequency-time spectrograms obtained by the DEMETER spacecraft (2004-2010, altitude about 700 km) revealed that the intensity of fractional hop whistlers is sometimes significantly reduced at specific frequencies. These frequencies are typically above about 3.4 kHz (second cutoff frequency of the Earth-ionosphere waveguide), and they vary smoothly in time. The events were explained by the wave propagation in the Earth-ionosphere waveguide, and a resulting interference of the first few waveguide modes. We analyze the events whose frequency-time structure is rather similar, but at frequencies below 1 kHz. Altogether, 284 events are identified during the periods with active Burst mode, when high resolution data are measured by DEMETER. The vast majority of events (93%) occurs during the nighttime. All six electromagnetic field components are available, which allows us to perform a detailed wave analysis. An overview of the properties of these events is presented, and their possible origin is discussed.

  15. Ion sense of polarization of the electromagnetic wave field in the electron whistler frequency band

    Directory of Open Access Journals (Sweden)

    B. Lundin

    Full Text Available It is shown that the left-hand (or ion-type sense of polarization can appear in the field interference pattern of two plane electron whistler waves. Moreover, it is demonstrated that the ion-type polarized wave electric fields can be accompanied by the presence at the same observation point of electron-type polarized wave magnetic fields. The registration of ion-type polarized fields with frequencies between the highest ion gyrofrequency and the electron gyrofrequency in a cold, overdense plasma is a sufficient indication for the existence of an interference wave pattern, which can typically occur near artificial or natural reflecting magnetospheric plasma regions, inside waveguides (as in helicon discharges, for example, in fields resonantly emitted by beams of charged particles or, in principle, in some self-sustained, nonlinear wave field structures. A comparison with the conventional spectral matrix data processing approach is also presented in order to facilitate the calculations of the analyzed polarization parameters.

    Key words. Ionosphere (wave propagation Radio science (waves in plasma Space plasma physics (general or miscellaneous

  16. Direct ion heating in overdense plasmas through the Brillouin instability driven by relativistic whistler waves

    Science.gov (United States)

    Sano, Takayoshi; Hata, Masayasu; Iwata, Natsumi; Mima, Kunioki; Sentoku, Yasuhiko

    2017-10-01

    Strong magnetic fields over kilo-Tesla have been available in the laboratory by the use of ultra-intense lasers. It would be interesting to apply those strong fields to other laser experiments such as the inertial confinement fusion and laboratory astrophysics. The characteristics of laser-plasma interactions could be modified significantly by the presence of such strong magnetic fields. We investigate electromagnetic wave propagation in overdense plasmas along the magnetic field for a right-hand circularly polarized wave by PIC simulations. Since the whistler mode has no cutoff density, it can penetrate into overdense plasmas and interact directly with charged particles there. When the external field strength is near a critical value defined by that the cyclotron frequency is equal to the laser one, it is reported that electrons are accelerated efficiently by the cyclotron resonance. However, if the field strength is far beyond the critical value, the cyclotron resonance is inefficient, while the ions gain a large amount of energy directly from the laser light owning to the Brillouin scattering. As the result, only ions are heated up selectively. We will discuss about the application of this ion heating in dense plasmas. This work was supported by JSPS KAKENHI Grant Number JP15K21767.

  17. Observations Directly Linking Relativistic Electron Microbursts to Whistler Mode Chorus: Van Allen Probes and FIREBIRD II

    Science.gov (United States)

    Breneman, A. W.; Crew, A.; Sample, J.; Klumpar, D.; Johnson, A.; Agapitov, O.; Shumko, M.; Turner, D. L.; Santolik, O.; Wygant, J. R.; Cattell, C. A.; Thaller, S.; Blake, B.; Spence, H.; Kletzing, C. A.

    2017-11-01

    We present observations that provide the strongest evidence yet that discrete whistler mode chorus packets cause relativistic electron microbursts. On 20 January 2016 near 1944 UT the low Earth orbiting CubeSat Focused Investigations of Relativistic Electron Bursts: Intensity, Range, and Dynamics (FIREBIRD II) observed energetic microbursts (near L = 5.6 and MLT = 10.5) from its lower limit of 220 keV, to 1 MeV. In the outer radiation belt and magnetically conjugate, Van Allen Probe A observed rising-tone, lower band chorus waves with durations and cadences similar to the microbursts. No other waves were observed. This is the first time that chorus and microbursts have been simultaneously observed with a separation smaller than a chorus packet. A majority of the microbursts do not have the energy dispersion expected for trapped electrons bouncing between mirror points. This confirms that the electrons are rapidly (nonlinearly) scattered into the loss cone by a coherent interaction with the large amplitude (up to ˜900 pT) chorus. Comparison of observed time-averaged microburst flux and estimated total electron drift shell content at L = 5.6 indicate that microbursts may represent a significant source of energetic electron loss in the outer radiation belt.

  18. Chorus whistler wave source scales as determined from multipoint Van Allen Probe measurements

    Science.gov (United States)

    Agapitov, Oleksiy; Mozer, Forrest; Blum, Lauren; Bonnell, John; Wygant, John

    2017-04-01

    Whistler-mode chorus waves are a particularly important process in outer radiation belt dynamics due to their key role in controlling the acceleration and scattering of electrons over a very wide energy range. The key parameters for both nonlinear and quasi-linear treatment of wave-particle interactions are the temporal and spatial scales of the wave source region and coherence of the wave field perturbations. Both of these scales, the source scale and the coherence scale, are not well-established experimentally, mostly because of a lack of VLF waveform data. We present an unprecedentedly long interval of coordinated VLF waveform measurements (sampled at 16384 s-1) aboard the two Van Allen Probes spacecraft. The cross spacecraft distance varied from about 100 up to 5000 km. Using time-domain correlation techniques, the chorus source regions have been determined to be about 450-550 km for upper band chorus waves with amplitude less than 100 pT and up to 1000 km for larger amplitude lower band chorus waves. The ratio between wave amplitudes measured on the two spacecraft is also examined and reveals that the wave amplitude distribution within a region of chorus element generation can be well approximated by the Gaussian with the characteristic distance r0 around 300 km. This work was supported by the JHU/APL contract 922613 (RBSP-EFW) and NASA Grant NNX16AF85G.

  19. Oblique propagation of whistler mode waves in the chorus source region

    Science.gov (United States)

    Santolík, O.; Gurnett, D. A.; Pickett, J. S.; Chum, J.; Cornilleau-Wehrlin, N.

    2009-12-01

    Whistler mode chorus has been shown to play a role in the process of local acceleration of electrons in the outer Van Allen radiation belt. Most of the quasi-linear and nonlinear theoretical studies assume that the waves propagate parallel to the terrestrial magnetic field. We show a case where this assumption is invalid. We use data from the Cluster spacecraft to characterize propagation and spectral properties of chorus. The recorded high-resolution waveforms show that chorus in the source region can be formed by a succession of discrete wave packets with decreasing frequency that sometimes change into shapeless hiss. These changes occur at the same time in the entire source region. Multicomponent measurements show that waves in both these regimes can be found at large angles to the terrestrial magnetic field. The hiss intervals contain waves propagating less than one tenth of a degree from the resonance cone. In the regime of discrete wave packets the peak of the wave energy density is found at a few degrees from the resonance cone in a broad interval of azimuth angles. The wave intensity increases with the distance from the magnetic field minimum along a given field line, indicating a gradual amplification of chorus in the source region.

  20. Ion sense of polarization of the electromagnetic wave field in the electron whistler frequency band

    Directory of Open Access Journals (Sweden)

    B. Lundin

    2002-08-01

    Full Text Available It is shown that the left-hand (or ion-type sense of polarization can appear in the field interference pattern of two plane electron whistler waves. Moreover, it is demonstrated that the ion-type polarized wave electric fields can be accompanied by the presence at the same observation point of electron-type polarized wave magnetic fields. The registration of ion-type polarized fields with frequencies between the highest ion gyrofrequency and the electron gyrofrequency in a cold, overdense plasma is a sufficient indication for the existence of an interference wave pattern, which can typically occur near artificial or natural reflecting magnetospheric plasma regions, inside waveguides (as in helicon discharges, for example, in fields resonantly emitted by beams of charged particles or, in principle, in some self-sustained, nonlinear wave field structures. A comparison with the conventional spectral matrix data processing approach is also presented in order to facilitate the calculations of the analyzed polarization parameters.Key words. Ionosphere (wave propagation Radio science (waves in plasma Space plasma physics (general or miscellaneous

  1. Space-time evolution of whistler mode wave growth in the magnetosphere

    International Nuclear Information System (INIS)

    Carlson, C.R.; Helliwell, R.A.; Inan, U.S.

    1990-01-01

    A new model is developed to simulate the space-time evolution of a propagating coherent whistler mode wave pulse in the magnetosphere. The model is applied to the case of single frequency (2-6 kHz) wave pulses injected into the magnetosphere near L ≅ 4, using the VLF transmitting facility at Siple Station, Antarctica. The mechanism for growth is cyclotron resonance between the circularly polarized waves and the gyrating energetic electrons of the radiation belts. Application of this model reproduces observed exponential wave growth up to a saturated level. Additionally, the model predicts the observed initial linear increase in the output frequency versus time. This is the first time these features have been reproduced using applied wave intensities small enough to be consistent with satellite measurements. The center velocities of the electrons entering the wave pulse are selected in a way which maximizes the growth rate. The results show the importance of the transient aspects in the wave growth process. The growth established as the wave propagates toward the geomagnetic equator results in a spatially advancing wave phase structure due mainly to the geomagnetic inhomogeneity. Through the feedback of this radiation upon other electrons, conditions are established which result in a linearly increasing output frequency with time

  2. The ATLAS Trigger System

    CERN Document Server

    Hauser, R

    2004-01-01

    ATLAS is one of two general-purpose detectors at the next generation proton-proton collider, the LHC. The high rate of interactions and the large number of read-out channels make the trigger system for ATLAS a challenging task. The initial bunch crossing rate of 40~MHz has to be reduced to about 200 Hz while preserving the physics signals against a large background. ATLAS uses a three-level trigger system, with the first level implemented in custom hardware, while the high level trigger systems are implemented in software on commodity hardware. This note describes the physics motivation, the various selection strategies for different channels as well as the physical implementation of the trigger system.

  3. Calo trigger acquisition system

    CERN Multimedia

    Franchini, Matteo

    2016-01-01

    Calo trigger acquisition system - Evolution of the acquisition system from a multiple boards system (upper, orange cables) to a single board one (below, light blue cables) where all the channels are collected in a single board.

  4. Asthma Triggers: Gain Control

    Science.gov (United States)

    ... in your house and may trigger asthma. Your asthma or your child's asthma may be worse around products such as ... You Can Take If you find that your asthma or your child's asthma gets worse when you use a certain ...

  5. Calorimetry triggering in ATLAS

    CERN Document Server

    Igonkina, O; Adragna, P; Aharrouche, M; Alexandre, G; Andrei, V; Anduaga, X; Aracena, I; Backlund, S; Baines, J; Barnett, B M; Bauss, B; Bee, C; Behera, P; Bell, P; Bendel, M; Benslama, K; Berry, T; Bogaerts, A; Bohm, C; Bold, T; Booth, J R A; Bosman, M; Boyd, J; Bracinik, J; Brawn, I, P; Brelier, B; Brooks, W; Brunet, S; Bucci, F; Casadei, D; Casado, P; Cerri, A; Charlton, D G; Childers, J T; Collins, N J; Conde Muino, P; Coura Torres, R; Cranmer, K; Curtis, C J; Czyczula, Z; Dam, M; Damazio, D; Davis, A O; De Santo, A; Degenhardt, J; Delsart, P A; Demers, S; Demirkoz, B; Di Mattia, A; Diaz, M; Djilkibaev, R; Dobson, E; Dova, M, T; Dufour, M A; Eckweiler, S; Ehrenfeld, W; Eifert, T; Eisenhandler, E; Ellis, N; Emeliyanov, D; Enoque Ferreira de Lima, D; Faulkner, P J W; Ferland, J; Flacher, H; Fleckner, J E; Flowerdew, M; Fonseca-Martin, T; Fratina, S; Fhlisch, F; Gadomski, S; Gallacher, M P; Garitaonandia Elejabarrieta, H; Gee, C N P; George, S; Gillman, A R; Goncalo, R; Grabowska-Bold, I; Groll, M; Gringer, C; Hadley, D R; Haller, J; Hamilton, A; Hanke, P; Hauser, R; Hellman, S; Hidvgi, A; Hillier, S J; Hryn'ova, T; Idarraga, J; Johansen, M; Johns, K; Kalinowski, A; Khoriauli, G; Kirk, J; Klous, S; Kluge, E-E; Koeneke, K; Konoplich, R; Konstantinidis, N; Kwee, R; Landon, M; LeCompte, T; Ledroit, F; Lei, X; Lendermann, V; Lilley, J N; Losada, M; Maettig, S; Mahboubi, K; Mahout, G; Maltrana, D; Marino, C; Masik, J; Meier, K; Middleton, R P; Mincer, A; Moa, T; Monticelli, F; Moreno, D; Morris, J D; Mller, F; Navarro, G A; Negri, A; Nemethy, P; Neusiedl, A; Oltmann, B; Olvito, D; Osuna, C; Padilla, C; Panes, B; Parodi, F; Perera, V J O; Perez, E; Perez Reale, V; Petersen, B; Pinzon, G; Potter, C; Prieur, D P F; Prokishin, F; Qian, W; Quinonez, F; Rajagopalan, S; Reinsch, A; Rieke, S; Riu, I; Robertson, S; Rodriguez, D; Rogriquez, Y; Rhr, F; Saavedra, A; Sankey, D P C; Santamarina, C; Santamarina Rios, C; Scannicchio, D; Schiavi, C; Schmitt, K; Schultz-Coulon, H C; Schfer, U; Segura, E; Silverstein, D; Silverstein, S; Sivoklokov, S; Sjlin, J; Staley, R J; Stamen, R; Stelzer, J; Stockton, M C; Straessner, A; Strom, D; Sushkov, S; Sutton, M; Tamsett, M; Tan, C L A; Tapprogge, S; Thomas, J P; Thompson, P D; Torrence, E; Tripiana, M; Urquijo, P; Urrejola, P; Vachon, B; Vercesi, V; Vorwerk, V; Wang, M; Watkins, P M; Watson, A; Weber, P; Weidberg, T; Werner, P; Wessels, M; Wheeler-Ellis, S; Whiteson, D; Wiedenmann, W; Wielers, M; Wildt, M; Winklmeier, F; Wu, X; Xella, S; Zhao, L; Zobernig, H; de Seixas, J M; dos Anjos, A; Asman, B; Özcan, E

    2009-01-01

    The ATLAS experiment is preparing for data taking at 14 TeV collision energy. A rich discovery physics program is being prepared in addition to the detailed study of Standard Model processes which will be produced in abundance. The ATLAS multi-level trigger system is designed to accept one event in 2 105 to enable the selection of rare and unusual physics events. The ATLAS calorimeter system is a precise instrument, which includes liquid Argon electro-magnetic and hadronic components as well as a scintillator-tile hadronic calorimeter. All these components are used in the various levels of the trigger system. A wide physics coverage is ensured by inclusively selecting events with candidate electrons, photons, taus, jets or those with large missing transverse energy. The commissioning of the trigger system is being performed with cosmic ray events and by replaying simulated Monte Carlo events through the trigger and data acquisition system.

  6. The ATLAS Trigger System

    CERN Document Server

    Owen, Rhys Edward; The ATLAS collaboration

    2018-01-01

    The ATLAS experiment employs a complex trigger system to enable the collaborations physics program. The LHC is now well in to its second running period delivering proton proton collisions at $\\sqrt{s}=13$ TeV with high instantaneous luminosity. This talk will describe the two level hardware and software trigger used to select events in this environment including recent improvements and the latest performance results.

  7. 2017 Tau Trigger Efficiencies

    CERN Document Server

    CMS Collaboration

    2018-01-01

    Triggers selecting events with hadronically decaying $\\tau$ leptons ($\\tau_h$) are used in a wide variety of CMS analyses, in particular those targeting processes with a $H \\rightarrow \\tau\\tau$ decay. The performance of the $\\tau_h$ triggers is presented for data collected in 2017, corresponding to an integrated luminosity of 41.5\\,fb$^{-1}$ at 13 TeV, and compared with simulation.

  8. LHCb Topological Trigger Reoptimization

    CERN Document Server

    INSPIRE-00400931; Ilten, Philip; Khairullin, Egor; Rogozhnikov, Alex; Ustyuzhanin, Andrey; Williams, Michael

    2015-12-23

    The main b-physics trigger algorithm used by the LHCb experiment is the so-called topological trigger. The topological trigger selects vertices which are a) detached from the primary proton-proton collision and b) compatible with coming from the decay of a b-hadron. In the LHC Run 1, this trigger, which utilized a custom boosted decision tree algorithm, selected a nearly 100% pure sample of b-hadrons with a typical efficiency of 60-70%; its output was used in about 60% of LHCb papers. This talk presents studies carried out to optimize the topological trigger for LHC Run 2. In particular, we have carried out a detailed comparison of various machine learning classifier algorithms, e.g., AdaBoost, MatrixNet and neural networks. The topological trigger algorithm is designed to select all "interesting" decays of b-hadrons, but cannot be trained on every such decay. Studies have therefore been performed to determine how to optimize the performance of the classification algorithm on decays not used in the training. ...

  9. Topological Trigger Developments

    CERN Multimedia

    Likhomanenko, Tatiana

    2015-01-01

    The main b-physics trigger algorithm used by the LHCb experiment is the so-called topological trigger. The topological trigger selects vertices which are a) detached from the primary proton-proton collision and b) compatible with coming from the decay of a b-hadron. In the LHC Run 1, this trigger utilized a custom boosted decision tree algorithm, selected an almost 100% pure sample of b-hadrons with a typical efficiency of 60-70%, and its output was used in about 60% of LHCb papers. This talk presents studies carried out to optimize the topological trigger for LHC Run 2. In particular, we have carried out a detailed comparison of various machine learning classifier algorithms, e.g., AdaBoost, MatrixNet and uBoost. The topological trigger algorithm is designed to select all "interesting" decays of b-hadrons, but cannot be trained on every such decay. Studies have therefore been performed to determine how to optimize the performance of the classification algorithm on decays not used in the training. These inclu...

  10. CMS Trigger Performance

    CERN Document Server

    Donato, Silvio

    2017-01-01

    During its second run of operation (Run 2) which started in 2015, the LHC will deliver a peak instantaneous luminosity that may reach $2 \\cdot 10^{34}$ cm$^{-2}$s$^{-1}$ with an average pile-up of about 55, far larger than the design value. Under these conditions, the online event selection is a very challenging task. In CMS, it is realized by a two-level trigger system the Level-1 (L1) Trigger, implemented in custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the offline reconstruction software running on a computer farm. In order to face this challenge, the L1 trigger has been through a major upgrade compared to Run 1, whereby all electronic boards of the system have been replaced, allowing more sophisticated algorithms to be run online. Its last stage, the global trigger, is now able to perform complex selections and to compute high-level quantities, like invariant masses. Likewise, the algorithms that run in the HLT go through big improvements; in particular, new appr...

  11. The CMS trigger system

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Aşılar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Knünz, Valentin; König, Axel; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Matsushita, Takashi; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Strauss, Josef; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Lauwers, Jasper; Luyckx, Sten; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; Daci, Nadir; De Bruyn, Isabelle; Deroover, Kevin; Heracleous, Natalie; Keaveney, James; Lowette, Steven; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Van Parijs, Isis; Barria, Patrizia; Brun, Hugues; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Fasanella, Giuseppe; Favart, Laurent; Grebenyuk, Anastasia; Karapostoli, Georgia; Lenzi, Thomas; Léonard, Alexandre; Maerschalk, Thierry; Marinov, Andrey; Perniè, Luca; Randle-conde, Aidan; Reis, Thomas; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Crucy, Shannon; Dobur, Didar; Fagot, Alexis; Garcia, Guillaume; Gul, Muhammad; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Poyraz, Deniz; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Tytgat, Michael; Van Driessche, Ward; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Mertens, Alexandre; Musich, Marco; Nuttens, Claude; Perrini, Lucia; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Beliy, Nikita; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Fábio Lúcio; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Hamer, Matthias; Hensel, Carsten; Mora Herrera, Clemencia; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Melo Da Costa, Eliza; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; De Souza Santos, Angelo; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Hadjiiska, Roumyana; Iaydjiev, Plamen; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Cheng, Tongguang; Du, Ran; Jiang, Chun-Hua; Plestina, Roko; Romeo, Francesco; Shaheen, Sarmad Masood; Spiezia, Aniello; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Zhang, Huaqiao; Asawatangtrakuldee, Chayanit; Ban, Yong; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Micanovic, Sasa; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; El Sawy, Mai; Elgammal, Sherif; Ellithi Kamel, Ali; Mahmoud, Mohammed; Calpas, Betty; Kadastik, Mario; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Veelken, Christian; Eerola, Paula; Pekkanen, Juska; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Machet, Martina; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Zghiche, Amina; Antropov, Iurii; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Cadamuro, Luca; Chapon, Emilien; Charlot, Claude; Dahms, Torsten; Davignon, Olivier; Filipovic, Nicolas; Florent, Alice; Granier de Cassagnac, Raphael; Lisniak, Stanislav; Mastrolorenzo, Luca; Miné, Philippe; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Pigard, Philipp; Regnard, Simon; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Strebler, Thomas; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Buttignol, Michael; Chabert, Eric Christian; Chanon, Nicolas; Collard, Caroline; Conte, Eric; Coubez, Xavier; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Le Bihan, Anne-Catherine; Merlin, Jeremie Alexandre; Skovpen, Kirill; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Bernet, Colin; Boudoul, Gaelle; Bouvier, Elvire; Carrillo Montoya, Camilo Andres; Chierici, Roberto; Contardo, Didier; Courbon, Benoit; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Lagarde, Francois; Laktineh, Imad Baptiste; Lethuillier, Morgan; Mirabito, Laurent; Pequegnot, Anne-Laure; Perries, Stephane; Ruiz Alvarez, José David; Sabes, David; Sgandurra, Louis; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Toriashvili, Tengizi; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Edelhoff, Matthias; Feld, Lutz; Heister, Arno; Kiesel, Maximilian Knut; Klein, Katja; Lipinski, Martin; Ostapchuk, Andrey; Preuten, Marius; Raupach, Frank; Schael, Stefan; Schulte, Jan-Frederik; Verlage, Tobias; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Endres, Matthias; Erdmann, Martin; Erdweg, Sören; Esch, Thomas; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Knutzen, Simon; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Pook, Tobias; Radziej, Markus; Reithler, Hans; Rieger, Marcel; Scheuch, Florian; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Künsken, Andreas; Lingemann, Joschka; Nehrkorn, Alexander; Nowack, Andreas; Nugent, Ian Michael; Pistone, Claudia; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Asin, Ivan; Bartosik, Nazar; Behnke, Olaf; Behrens, Ulf; Bell, Alan James; Borras, Kerstin; Burgmeier, Armin; Campbell, Alan; Choudhury, Somnath; Costanza, Francesco; Diez Pardos, Carmen; Dolinska, Ganna; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Gallo, Elisabetta; Garay Garcia, Jasone; Geiser, Achim; Gizhko, Andrii; Gunnellini, Paolo; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kalogeropoulos, Alexis; Karacheban, Olena; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Korol, Ievgen; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Mankel, Rainer; Marfin, Ihar; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Nayak, Aruna; Ntomari, Eleni; Perrey, Hanno; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Roland, Benoit; Sahin, Mehmet Özgür; Saxena, Pooja; Schoerner-Sadenius, Thomas; Schröder, Matthias; Seitz, Claudia; Spannagel, Simon; Trippkewitz, Karim Damun; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Gonzalez, Daniel; Görner, Martin; Haller, Johannes; Hoffmann, Malte; Höing, Rebekka Sophie; Junkes, Alexandra; Klanner, Robert; Kogler, Roman; Kovalchuk, Nataliia; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Marconi, Daniele; Meyer, Mareike; Nowatschin, Dominik; Ott, Jochen; Pantaleo, Felice; Peiffer, Thomas; Perieanu, Adrian; Pietsch, Niklas; Poehlsen, Jennifer; Rathjens, Denis; Sander, Christian; Scharf, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Schwandt, Joern; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Tholen, Heiner; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Vormwald, Benedikt; Akbiyik, Melike; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; Colombo, Fabio; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Fink, Simon; Frensch, Felix; Friese, Raphael; Giffels, Manuel; Gilbert, Andrew; Haitz, Dominik; Hartmann, Frank; Heindl, Stefan Michael; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Lobelle Pardo, Patricia; Maier, Benedikt; Mildner, Hannes; Mozer, Matthias Ulrich; Müller, Thomas; Müller, Thomas; Plagge, Michael; Quast, Gunter; Rabbertz, Klaus; Röcker, Steffen; Roscher, Frank; Sieber, Georg; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weber, Marc; Weiler, Thomas; Wöhrmann, Clemens; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Psallidas, Andreas; Topsis-Giotis, Iasonas; Agapitos, Antonis; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Tziaferi, Eirini; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Loukas, Nikitas; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Strologas, John; Bencze, Gyorgy; Hajdu, Csaba; Hazi, Andras; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Molnar, Jozsef; Szillasi, Zoltan; Bartók, Márton; Makovec, Alajos; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Mal, Prolay; Mandal, Koushik; Sahoo, Deepak Kumar; Sahoo, Niladribihari; Swain, Sanjay Kumar; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Chawla, Ridhi; Gupta, Ruchi; Bhawandeep, Bhawandeep; Kalsi, Amandeep Kaur; Kaur, Anterpreet; Kaur, Manjit; Kumar, Ramandeep; Mehta, Ankita; Mittal, Monika; Singh, Jasbir; Walia, Genius; Kumar, Ashok; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Garg, Rocky Bala; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Nishu, Nishu; Ranjan, Kirti; Sharma, Ramkrishna; Sharma, Varun; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dey, Sourav; Dutta, Suchandra; Jain, Sandhya; Majumdar, Nayana; Modak, Atanu; Mondal, Kuntal; Mukherjee, Swagata; Mukhopadhyay, Supratik; Roy, Ashim; Roy, Debarati; Roy Chowdhury, Suvankar; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Chudasama, Ruchi; Dutta, Dipanwita; Jha, Vishwajeet; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Banerjee, Sudeshna; Bhowmik, Sandeep; Chatterjee, Rajdeep Mohan; Dewanjee, Ram Krishna; Dugad, Shashikant; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Kole, Gouranga; Kumar, Sanjeev; Mahakud, Bibhuprasad; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mitra, Soureek; Mohanty, Gagan Bihari; Parida, Bibhuti; Sarkar, Tanmay; Sur, Nairit; Sutar, Bajrang; Wickramage, Nadeesha; Chauhan, Shubhanshu; Dube, Sourabh; Kothekar, Kunal; Sharma, Seema; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Goldouzian, Reza; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Caputo, Claudio; Colaleo, Anna; Creanza, Donato; Cristella, Leonardo; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; Miniello, Giorgia; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Ranieri, Antonio; Selvaggi, Giovanna; Silvestris, Lucia; Venditti, Rosamaria; Verwilligen, Piet; Abbiendi, Giovanni; Battilana, Carlo; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Chhibra, Simranjit Singh; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Di Mattia, Alessandro; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gonzi, Sandro; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Viliani, Lorenzo; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Primavera, Federica; Calvelli, Valerio; Ferro, Fabrizio; Lo Vetere, Maurizio; Monge, Maria Roberta; Robutti, Enrico; Tosi, Silvano; Brianza, Luca; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Esposito, Marco; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lanza, Giuseppe; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Sciacca, Crisostomo; Thyssen, Filip; Bacchetta, Nicola; Bellato, Marco; Benato, Lisa; Bisello, Dario; Boletti, Alessio; Carlin, Roberto; Checchia, Paolo; Dall'Osso, Martino; Dosselli, Umberto; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Montecassiano, Fabio; Passaseo, Marina; Pazzini, Jacopo; Pegoraro, Matteo; Pozzobon, Nicola; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Vanini, Sara; Ventura, Sandro; Zanetti, Marco; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Braghieri, Alessandro; Magnani, Alice; Montagna, Paolo; Ratti, Sergio P; Re, Valerio; Riccardi, Cristina; Salvini, Paola; Vai, Ilaria; Vitulo, Paolo; Alunni Solestizi, Luisa; Biasini, Maurizio; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fedi, Giacomo; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Serban, Alin Titus; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; D'imperio, Giulia; Del Re, Daniele; Diemoz, Marcella; Gelli, Simone; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Organtini, Giovanni; Paramatti, Riccardo; Preiato, Federico; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Traczyk, Piotr; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Costa, Marco; Covarelli, Roberto; Degano, Alessandro; Demaria, Natale; Finco, Linda; Kiani, Bilal; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Monteil, Ennio; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Ravera, Fabio; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Tamponi, Umberto; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Marone, Matteo; Schizzi, Andrea; Zanetti, Anna; Kropivnitskaya, Anna; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Oh, Young Do; Sakharov, Alexandre; Son, Dong-Chul; Brochero Cifuentes, Javier Andres; Kim, Hyunsoo; Kim, Tae Jeong; Song, Sanghyeon; Choi, Suyong; Go, Yeonju; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kisoo; Lee, Kyong Sei; Lee, Songkyo; Park, Sung Keun; Roh, Youn; Yoo, Hwi Dong; Choi, Minkyoo; Kim, Hyunyong; Kim, Ji Hyun; Lee, Jason Sang Hun; Park, Inkyu; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Goh, Junghwan; Kim, Donghyun; Kwon, Eunhyang; Lee, Jongseok; Yu, Intae; Dudenas, Vytautas; Juodagalvis, Andrius; Vaitkus, Juozas; Ahmed, Ijaz; Ibrahim, Zainol Abidin; Komaragiri, Jyothsna Rani; Md Ali, Mohd Adli Bin; Mohamad Idris, Faridah; Wan Abdullah, Wan Ahmad Tajuddin; Yusli, Mohd Nizam; Casimiro Linares, Edgar; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-De La Cruz, Ivan; Hernandez-Almada, Alberto; Lopez-Fernandez, Ricardo; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khan, Wajid Ali; Khurshid, Taimoor; Shoaib, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Byszuk, Adrian; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Pozniak, Krzysztof; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Leonardo, Nuno; Lloret Iglesias, Lara; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Konoplyanikov, Viktor; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Vlasov, Evgueni; Zhokin, Alexander; Bylinkin, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Kaminskiy, Alexandre; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Navarro De Martino, Eduardo; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Senghi Soares, Mara; Albajar, Carmen; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Palencia Cortezon, Enrique; Vizan Garcia, Jesus Manuel; Cabrillo, Iban Jose; Calderon, Alicia; Castiñeiras De Saa, Juan Ramon; De Castro Manzano, Pablo; Duarte Campderros, Jordi; Fernandez, Marcos; Garcia-Ferrero, Juan; Gomez, Gervasio; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Trevisani, Nicolò; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Bendavid, Joshua; Benhabib, Lamia; Benitez, Jose F; Berruti, Gaia Maria; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Castello, Roberto; Cerminara, Gianluca; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; Daponte, Vincenzo; David Tinoco Mendes, Andre; De Gruttola, Michele; De Guio, Federico; De Roeck, Albert; De Visscher, Simon; Di Marco, Emanuele; Dobson, Marc; Dordevic, Milos; Dorney, Brian; Du Pree, Tristan; Dünser, Marc; Dupont, Niels; Elliott-Peisert, Anna; Franzoni, Giovanni; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Girone, Maria; Glege, Frank; Guida, Roberto; Gundacker, Stefan; Guthoff, Moritz; Hammer, Josef; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Kirschenmann, Henning; Kortelainen, Matti J; Kousouris, Konstantinos; Krajczar, Krisztian; Lecoq, Paul; Lourenco, Carlos; Lucchini, Marco Toliman; Magini, Nicolo; Malgeri, Luca; Mannelli, Marcello; Martelli, Arabella; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moortgat, Filip; Morovic, Srecko; Mulders, Martijn; Nemallapudi, Mythra Varun; Neugebauer, Hannes; Orfanelli, Styliani; Orsini, Luciano; Pape, Luc; Perez, Emmanuelle; Peruzzi, Marco; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Piparo, Danilo; Racz, Attila; Rolandi, Gigi; Rovere, Marco; Ruan, Manqi; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Seidel, Markus; Sharma, Archana; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Steggemann, Jan; Stieger, Benjamin; Stoye, Markus; Takahashi, Yuta; Treille, Daniel; Triossi, Andrea; Tsirou, Andromachi; Veres, Gabor Istvan; Wardle, Nicholas; Wöhri, Hermine Katharina; Zagoździńska, Agnieszka; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; Kotlinski, Danek; Langenegger, Urs; Renker, Dieter; Rohe, Tilman; Bachmair, Felix; Bäni, Lukas; Bianchini, Lorenzo; Casal, Bruno; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Eller, Philipp; Grab, Christoph; Heidegger, Constantin; Hits, Dmitry; Hoss, Jan; Kasieczka, Gregor; Lustermann, Werner; Mangano, Boris; Marionneau, Matthieu; Martinez Ruiz del Arbol, Pablo; Masciovecchio, Mario; Meister, Daniel; Micheli, Francesco; Musella, Pasquale; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pata, Joosep; Pauss, Felicitas; Perrozzi, Luca; Quittnat, Milena; Rossini, Marco; Starodumov, Andrei; Takahashi, Maiko; Tavolaro, Vittorio Raoul; Theofilatos, Konstantinos; Wallny, Rainer; Aarrestad, Thea Klaeboe; Amsler, Claude; Caminada, Lea; Canelli, Maria Florencia; Chiochia, Vincenzo; De Cosa, Annapaola; Galloni, Camilla; Hinzmann, Andreas; Hreus, Tomas; Kilminster, Benjamin; Lange, Clemens; Ngadiuba, Jennifer; Pinna, Deborah; Robmann, Peter; Ronga, Frederic Jean; Salerno, Daniel; Yang, Yong; Cardaci, Marco; Chen, Kuan-Hsin; Doan, Thi Hien; Jain, Shilpi; Khurana, Raman; Konyushikhin, Maxim; Kuo, Chia-Ming; Lin, Willis; Lu, Yun-Ju; Yu, Shin-Shan; Kumar, Arun; Bartek, Rachel; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Dietz, Charles; Fiori, Francesco; Grundler, Ulysses; Hou, George Wei-Shu; Hsiung, Yee; Liu, Yueh-Feng; Lu, Rong-Shyang; Miñano Moya, Mercedes; Petrakou, Eleni; Tsai, Jui-fa; Tzeng, Yeng-Ming; Asavapibhop, Burin; Kovitanggoon, Kittikul; Singh, Gurpreet; Srimanobhas, Norraphat; Suwonjandee, Narumon; Adiguzel, Aytul; Bakirci, Mustafa Numan; Demiroglu, Zuhal Seyma; Dozen, Candan; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Onengut, Gulsen; Ozdemir, Kadri; Polatoz, Ayse; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Vergili, Mehmet; Zorbilmez, Caglar; Akin, Ilina Vasileva; Bilin, Bugra; Bilmis, Selcuk; Isildak, Bora; Karapinar, Guler; Yalvac, Metin; Zeyrek, Mehmet; Gülmez, Erhan; Kaya, Mithat; Kaya, Ozlem; Yetkin, Elif Asli; Yetkin, Taylan; Cakir, Altan; Cankocak, Kerem; Sen, Sercan; Vardarlı, Fuat Ilkehan; Grynyov, Boris; Levchuk, Leonid; Sorokin, Pavel; Aggleton, Robin; Ball, Fionn; Beck, Lana; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Meng, Zhaoxia; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Sakuma, Tai; Seif El Nasr-storey, Sarah; Senkin, Sergey; Smith, Dominic; Smith, Vincent J; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Calligaris, Luigi; Cieri, Davide; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; Thea, Alessandro; Tomalin, Ian R; Williams, Thomas; Womersley, William John; Worm, Steven; Baber, Mark; Bainbridge, Robert; Buchmuller, Oliver; Bundock, Aaron; Burton, Darren; Casasso, Stefano; Citron, Matthew; Colling, David; Corpe, Louie; Cripps, Nicholas; Dauncey, Paul; Davies, Gavin; De Wit, Adinda; Della Negra, Michel; Dunne, Patrick; Elwood, Adam; Ferguson, William; Fulcher, Jonathan; Futyan, David; Hall, Geoffrey; Iles, Gregory; Kenzie, Matthew; Lane, Rebecca; Lucas, Robyn; Lyons, Louis; Magnan, Anne-Marie; Malik, Sarah; Nash, Jordan; Nikitenko, Alexander; Pela, Joao; Pesaresi, Mark; Petridis, Konstantinos; Raymond, David Mark; Richards, Alexander; Rose, Andrew; Seez, Christopher; Tapper, Alexander; Uchida, Kirika; Vazquez Acosta, Monica; Virdee, Tejinder; Zenz, Seth Conrad; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leggat, Duncan; Leslie, Dawn; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Borzou, Ahmad; Call, Kenneth; Dittmann, Jay; Hatakeyama, Kenichi; Liu, Hongxuan; Pastika, Nathaniel; Charaf, Otman; Cooper, Seth; Henderson, Conor; Rumerio, Paolo; Arcaro, Daniel; Avetisyan, Aram; Bose, Tulika; Fantasia, Cory; Gastler, Daniel; Lawson, Philip; Rankin, Dylan; Richardson, Clint; Rohlf, James; St John, Jason; Sulak, Lawrence; Zou, David; Alimena, Juliette; Berry, Edmund; Bhattacharya, Saptaparna; Cutts, David; Dhingra, Nitish; Ferapontov, Alexey; Garabedian, Alex; Hakala, John; Heintz, Ulrich; Laird, Edward; Landsberg, Greg; Mao, Zaixing; Narain, Meenakshi; Piperov, Stefan; Sagir, Sinan; Syarif, Rizki; Breedon, Richard; Breto, Guillermo; Calderon De La Barca Sanchez, Manuel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Erbacher, Robin; Gardner, Michael; Ko, Winston; Lander, Richard; Mulhearn, Michael; Pellett, Dave; Pilot, Justin; Ricci-Tam, Francesca; Shalhout, Shalhout; Smith, John; Squires, Michael; Stolp, Dustin; Tripathi, Mani; Wilbur, Scott; Yohay, Rachel; Cousins, Robert; Everaerts, Pieter; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Saltzberg, David; Takasugi, Eric; Valuev, Vyacheslav; Weber, Matthias; Burt, Kira; Clare, Robert; Ellison, John Anthony; Gary, J William; Hanson, Gail; Heilman, Jesse; Paneva, Mirena Ivova; Jandir, Pawandeep; Kennedy, Elizabeth; Lacroix, Florent; Long, Owen Rosser; Luthra, Arun; Malberti, Martina; Olmedo Negrete, Manuel; Shrinivas, Amithabh; Wei, Hua; Wimpenny, Stephen; Yates, Brent; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; D'Agnolo, Raffaele Tito; Derdzinski, Mark; Holzner, André; Kelley, Ryan; Klein, Daniel; Letts, James; Macneill, Ian; Olivito, Dominick; Padhi, Sanjay; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Tadel, Matevz; Vartak, Adish; Wasserbaech, Steven; Welke, Charles; Würthwein, Frank; Yagil, Avraham; Zevi Della Porta, Giovanni; Bradmiller-Feld, John; Campagnari, Claudio; Dishaw, Adam; Dutta, Valentina; Flowers, Kristen; Franco Sevilla, Manuel; Geffert, Paul; George, Christopher; Golf, Frank; Gouskos, Loukas; Gran, Jason; Incandela, Joe; Mccoll, Nickolas; Mullin, Sam Daniel; Richman, Jeffrey; Stuart, David; Suarez, Indara; West, Christopher; Yoo, Jaehyeok; Anderson, Dustin; Apresyan, Artur; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Duarte, Javier; Mott, Alexander; Newman, Harvey B; Pena, Cristian; Pierini, Maurizio; Spiropulu, Maria; Vlimant, Jean-Roch; Xie, Si; Zhu, Ren-Yuan; Andrews, Michael Benjamin; Azzolini, Virginia; Calamba, Aristotle; Carlson, Benjamin; Ferguson, Thomas; Paulini, Manfred; Russ, James; Sun, Menglei; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Ford, William T; Gaz, Alessandro; Jensen, Frank; Johnson, Andrew; Krohn, Michael; Mulholland, Troy; Nauenberg, Uriel; Stenson, Kevin; Wagner, Stephen Robert; Alexander, James; Chatterjee, Avishek; Chaves, Jorge; Chu, Jennifer; Dittmer, Susan; Eggert, Nicholas; Mirman, Nathan; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Rinkevicius, Aurelijus; Ryd, Anders; Skinnari, Louise; Soffi, Livia; Sun, Werner; Tan, Shao Min; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Tucker, Jordan; Weng, Yao; Wittich, Peter; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Banerjee, Sunanda; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bolla, Gino; Burkett, Kevin; Butler, Joel Nathan; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hanlon, Jim; Hare, Daryl; Harris, Robert M; Hasegawa, Satoshi; Hirschauer, James; Hu, Zhen; Jayatilaka, Bodhitha; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Jung, Andreas Werner; Klima, Boaz; Kreis, Benjamin; Kwan, Simon; Lammel, Stephan; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Liu, Tiehui; Lopes De Sá, Rafael; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Martinez Outschoorn, Verena Ingrid; Maruyama, Sho; Mason, David; McBride, Patricia; Merkel, Petra; Mishra, Kalanand; Mrenna, Stephen; Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Pedro, Kevin; Prokofyev, Oleg; Rakness, Gregory; Sexton-Kennedy, Elizabeth; Soha, Aron; Spalding, William J; Spiegel, Leonard; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vernieri, Caterina; Verzocchi, Marco; Vidal, Richard; Weber, Hannsjoerg Artur; Whitbeck, Andrew; Yang, Fan; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Bourilkov, Dimitri; Carnes, Andrew; Carver, Matthew; Curry, David; Das, Souvik; Di Giovanni, Gian Piero; Field, Richard D; Furic, Ivan-Kresimir; Gleyzer, Sergei V; Hugon, Justin; Konigsberg, Jacobo; Korytov, Andrey; Low, Jia Fu; Ma, Peisen; Matchev, Konstantin; Mei, Hualin; Milenovic, Predrag; Mitselmakher, Guenakh; Rank, Douglas; Rossin, Roberto; Shchutska, Lesya; Snowball, Matthew; Sperka, David; Terentyev, Nikolay; Thomas, Laurent; Wang, Jian; Wang, Sean-Jiun; Yelton, John; Hewamanage, Samantha; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Ackert, Andrew; Adams, Jordon Rowe; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Diamond, Brendan; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Khatiwada, Ajeeta; Prosper, Harrison; Weinberg, Marc; Baarmand, Marc M; Bhopatkar, Vallary; Colafranceschi, Stefano; Hohlmann, Marcus; Kalakhety, Himali; Noonan, Daniel; Roy, Titas; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Kurt, Pelin; O'Brien, Christine; Sandoval Gonzalez, Irving Daniel; Silkworth, Christopher; Turner, Paul; Varelas, Nikos; Wu, Zhenbin; Zakaria, Mohammed; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Durgut, Süleyman; Gandrajula, Reddy Pratap; Haytmyradov, Maksat; Khristenko, Viktor; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Snyder, Christina; Tiras, Emrah; Wetzel, James; Yi, Kai; Anderson, Ian; Barnett, Bruce Arnold; Blumenfeld, Barry; Eminizer, Nicholas; Fehling, David; Feng, Lei; Gritsan, Andrei; Maksimovic, Petar; Martin, Christopher; Osherson, Marc; Roskes, Jeffrey; Cocoros, Alice; Sarica, Ulascan; Swartz, Morris; Xiao, Meng; Xin, Yongjie; You, Can; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Bruner, Christopher; Kenny III, Raymond Patrick; Majumder, Devdatta; Malek, Magdalena; Murray, Michael; Sanders, Stephen; Stringer, Robert; Wang, Quan; Ivanov, Andrew; Kaadze, Ketino; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Mohammadi, Abdollah; Saini, Lovedeep Kaur; Skhirtladze, Nikoloz; Toda, Sachiko; Lange, David; Rebassoo, Finn; Wright, Douglas; Anelli, Christopher; Baden, Drew; Baron, Owen; Belloni, Alberto; Calvert, Brian; Eno, Sarah Catherine; Ferraioli, Charles; Gomez, Jaime; Hadley, Nicholas John; Jabeen, Shabnam; Kellogg, Richard G; Kolberg, Ted; Kunkle, Joshua; Lu, Ying; Mignerey, Alice; Shin, Young Ho; Skuja, Andris; Tonjes, Marguerite; Tonwar, Suresh C; Apyan, Aram; Barbieri, Richard; Baty, Austin; Bierwagen, Katharina; Brandt, Stephanie; Busza, Wit; Cali, Ivan Amos; Demiragli, Zeynep; Di Matteo, Leonardo; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Gulhan, Doga; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Marini, Andrea Carlo; Mcginn, Christopher; Mironov, Camelia; Narayanan, Siddharth; Niu, Xinmei; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Salfeld-Nebgen, Jakob; Stephans, George; Sumorok, Konstanty; Varma, Mukund; Velicanu, Dragos; Veverka, Jan; Wang, Jing; Wang, Ta-Wei; Wyslouch, Bolek; Yang, Mingming; Zhukova, Victoria; Dahmes, Bryan; Evans, Andrew; Finkel, Alexey; Gude, Alexander; Hansen, Peter; Kalafut, Sean; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Lesko, Zachary; Mans, Jeremy; Nourbakhsh, Shervin; Ruckstuhl, Nicole; Rusack, Roger; Tambe, Norbert; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Claes, Daniel R; Dominguez, Aaron; Fangmeier, Caleb; Gonzalez Suarez, Rebeca; Kamalieddin, Rami; Keller, Jason; Knowlton, Dan; Kravchenko, Ilya; Meier, Frank; Monroy, Jose; Ratnikov, Fedor; Siado, Joaquin Emilo; Snow, Gregory R; Alyari, Maral; Dolen, James; George, Jimin; Godshalk, Andrew; Harrington, Charles; Iashvili, Ia; Kaisen, Josh; Kharchilava, Avto; Kumar, Ashish; Rappoccio, Salvatore; Roozbahani, Bahareh; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Hortiangtham, Apichart; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Teixeira De Lima, Rafael; Trocino, Daniele; Wang, Ren-Jie; Wood, Darien; Zhang, Jinzhong; Hahn, Kristan Allan; Kubik, Andrew; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael Henry; Stoynev, Stoyan; Sung, Kevin; Trovato, Marco; Velasco, Mayda; Brinkerhoff, Andrew; Dev, Nabarun; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Lynch, Sean; Marinelli, Nancy; Meng, Fanbo; Mueller, Charles; Musienko, Yuri; Pearson, Tessa; Planer, Michael; Reinsvold, Allison; Ruchti, Randy; Smith, Geoffrey; Taroni, Silvia; Valls, Nil; Wayne, Mitchell; Wolf, Matthias; Woodard, Anna; Antonelli, Louis; Brinson, Jessica; Bylsma, Ben; Durkin, Lloyd Stanley; Flowers, Sean; Hart, Andrew; Hill, Christopher; Hughes, Richard; Ji, Weifeng; Kotov, Khristian; Ling, Ta-Yung; Liu, Bingxuan; Luo, Wuming; Puigh, Darren; Rodenburg, Marissa; Winer, Brian L; Wulsin, Howard Wells; Driga, Olga; Elmer, Peter; Hardenbrook, Joshua; Hebda, Philip; Koay, Sue Ann; Lujan, Paul; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Palmer, Christopher; Piroué, Pierre; Saka, Halil; Stickland, David; Tully, Christopher; Zuranski, Andrzej; Malik, Sudhir; Barnes, Virgil E; Benedetti, Daniele; Bortoletto, Daniela; Gutay, Laszlo; Jha, Manoj; Jones, Matthew; Jung, Kurt; Miller, David Harry; Neumeister, Norbert; Radburn-Smith, Benjamin Charles; Shi, Xin; Shipsey, Ian; Silvers, David; Sun, Jian; Svyatkovskiy, Alexey; Wang, Fuqiang; Xie, Wei; Xu, Lingshan; Parashar, Neeti; Stupak, John; Adair, Antony; Akgun, Bora; Chen, Zhenyu; Ecklund, Karl Matthew; Geurts, Frank JM; Guilbaud, Maxime; Li, Wei; Michlin, Benjamin; Northup, Michael; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Rorie, Jamal; Tu, Zhoudunming; Zabel, James; Betchart, Burton; Bodek, Arie; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Galanti, Mario; Garcia-Bellido, Aran; Han, Jiyeon; Harel, Amnon; Hindrichs, Otto; Khukhunaishvili, Aleko; Petrillo, Gianluca; Tan, Ping; Verzetti, Mauro; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Hughes, Elliot; Kaplan, Steven; Kunnawalkam Elayavalli, Raghav; Lath, Amitabh; Nash, Kevin; Panwalkar, Shruti; Park, Michael; Salur, Sevil; Schnetzer, Steve; Sheffield, David; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Foerster, Mark; Riley, Grant; Rose, Keith; Spanier, Stefan; York, Andrew; Bouhali, Othmane; Castaneda Hernandez, Alfredo; Dalchenko, Mykhailo; De Mattia, Marco; Delgado, Andrea; Dildick, Sven; Eusebi, Ricardo; Gilmore, Jason; Kamon, Teruki; Krutelyov, Vyacheslav; Mueller, Ryan; Osipenkov, Ilya; Pakhotin, Yuriy; Patel, Rishi; Perloff, Alexx; Rose, Anthony; Safonov, Alexei; Tatarinov, Aysen; Ulmer, Keith; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Kunori, Shuichi; Lamichhane, Kamal; Lee, Sung Won; Libeiro, Terence; Undleeb, Sonaina; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Greene, Senta; Gurrola, Alfredo; Janjam, Ravi; Johns, Willard; Maguire, Charles; Mao, Yaxian; Melo, Andrew; Ni, Hong; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Xu, Qiao; Arenton, Michael Wayne; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Lin, Chuanzhe; Neu, Christopher; Sinthuprasith, Tutanon; Sun, Xin; Wang, Yanchu; Wolfe, Evan; Wood, John; Xia, Fan; Clarke, Christopher; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Sturdy, Jared; Belknap, Donald; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Gomber, Bhawna; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Lanaro, Armando; Levine, Aaron; Long, Kenneth; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ruggles, Tyler; Sarangi, Tapas; Savin, Alexander; Sharma, Archana; Smith, Nicholas; Smith, Wesley H; Taylor, Devin; Woods, Nathaniel

    2017-01-24

    This paper describes the CMS trigger system and its performance during Run 1 of the LHC. The trigger system consists of two levels designed to select events of potential physics interest from a GHz (MHz) interaction rate of proton-proton (heavy ion) collisions. The first level of the trigger is implemented in hardware, and selects events containing detector signals consistent with an electron, photon, muon, $\\tau$ lepton, jet, or missing transverse energy. A programmable menu of up to 128 object-based algorithms is used to select events for subsequent processing. The trigger thresholds are adjusted to the LHC instantaneous luminosity during data taking in order to restrict the output rate to 100 kHz, the upper limit imposed by the CMS readout electronics. The second level, implemented in software, further refines the purity of the output stream, selecting an average rate of 400 Hz for offline event storage. The objectives, strategy and performance of the trigger system during the LHC Run 1 are described.

  12. SUPRATHERMAL ELECTRON STRAHL WIDTHS IN THE PRESENCE OF NARROW-BAND WHISTLER WAVES IN THE SOLAR WIND

    Energy Technology Data Exchange (ETDEWEB)

    Kajdič, P. [Instituto de Geofísica, Universidad Nacional Autónoma de México, Mexico City (Mexico); Alexandrova, O.; Maksimovic, M.; Lacombe, C. [LESIA, Observatoire de Paris, PSL Research University, CNRS, UPMC UniversitéParis 06, Université Paris-Diderot, 5 Place Jules Janssen, F-92190 Meudon (France); Fazakerley, A. N., E-mail: primoz@geofisica.unam.mx [Mullard Space Science Laboratory, University College London (United Kingdom)

    2016-12-20

    We perform the first statistical study of the effects of the interaction of suprathermal electrons with narrow-band whistler mode waves in the solar wind (SW). We show that this interaction does occur and that it is associated with enhanced widths of the so-called strahl component. The latter is directed along the interplanetary magnetic field away from the Sun. We do the study by comparing the strahl pitch angle widths in the SW at 1 AU in the absence of large scale discontinuities and transient structures, such as interplanetary shocks, interplanetary coronal mass ejections, stream interaction regions, etc. during times when the whistler mode waves were present and when they were absent. This is done by using the data from two Cluster instruments: Spatio Temporal Analysis of Field Fluctuations experiment (STAFF) data in the frequency range between ∼0.1 and ∼200 Hz were used for determining the wave properties and Plasma Electron And Current Experiment (PEACE) data sets at 12 central energies between ∼57 eV (equivalent to ∼10 typical electron thermal energies in the SW, E{sub T}) and ∼676 eV (∼113 E{sub T}) for pitch angle measurements. Statistical analysis shows that, during the intervals with the whistler waves, the strahl component on average exhibits pitch angle widths between 2° and 12° larger than during the intervals when these waves are not present. The largest difference is obtained for the electron central energy of ∼344 eV (∼57 ET).

  13. Whistler mode resonance-cone transmissions at 100 kHz in the OEDIPUS-C experiment

    Czech Academy of Sciences Publication Activity Database

    Chugunov, Y. V.; Fiala, Vladimír; Hayosh, Mykhaylo; James, H. G.

    2012-01-01

    Roč. 47, č. 6 (2012), RS6002/1-RS6002/11 ISSN 0048-6604 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100420904 Program:M Institutional support: RVO:68378289 Keywords : OEDIPUS-C * dipole * pulse distortion * resonance cone * whistler mode Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.000, year: 2012 http://onlinelibrary.wiley.com/doi/10.1029/2012RS005054/abstract

  14. Evidence for Asian dust effects from aerosol plume measurements during INTEX-B 2006 near Whistler, BC

    Directory of Open Access Journals (Sweden)

    W. R. Leaitch

    2009-06-01

    Full Text Available Several cases of aerosol plumes resulting from trans-Pacific transport were observed between 2 km and 5.3 km at Whistler, BC from 22 April 2006 to 15 May 2006. The fine particle (<1 μm chemical composition of most of the plumes was dominated by sulphate that ranged from 1–5 μg m−3 as measured with a Quadrapole Aerosol Mass Spectrometer (Q-AMS. Coarse particles (>1 μm were enhanced in all sulphate plumes. Fine particle organic mass concentrations were relatively low in most plumes and were nominally anti-correlated with the increases in the number concentrations of coarse particles. The ion chemistry of coarse particles sampled at Whistler Peak was dominated by calcium, sodium, nitrate, sulphate and formate. Scanning transmission X-ray microscopy of coarse particles sampled from the NCAR C-130 aircraft relatively close to Whistler indicated carbonate, potassium and organic functional groups, in particular the carboxyl group. Asian plumes reaching Whistler, BC during the INTEX-B study were not only significantly reduced of fine particle organic material, but organic compounds were attached to coarse particles in significant quantities. Suspension of dust with deposited organic material and scavenging of organic materials by dust near anthropogenic sources are suggested, and if any secondary organic aerosol (SOA was formed during transport from Asian source regions across the Pacific it was principally associated with the coarse particles. An average of profiles indicates that trans-Pacific transport between 2 and 5 km during this period increased ozone by about 10 ppbv and fine particle sulphate by 0.2–0.5 μg m−3. The mean sizes of the fine particles in the sulphate plumes were larger when dust particles were present and smaller when the fine particle organic mass concentration was larger and dust was absent. The coarse particles of dust act to accumulate sulphate, nitrate and organic material in larger particles

  15. Des estampes de Whistler en cadeau au CdAg : l'empreinte d'un donateur exceptionnel

    OpenAIRE

    Rümelin, Christian

    2018-01-01

    Tiré du site internet du blog des Musées d'art et d'histoire (http://blog.mahgeneve.ch): "En novembre dernier, le Cabinet d'arts graphiques des Musées d'art et d'histoire a eu le rare privilège de recevoir sept estampes de l'artiste américain James McNeill Whistler (Lowell, Massachusetts, 1834 – Chelsea, Londres, 1903). Un don exceptionnel, de la part d'amis d'Adriaan Van Ravesteijn (1938-2015).".

  16. Nonlinear local parallel acceleration of electrons through Landau trapping by oblique whistler mode waves in the outer radiation belt

    OpenAIRE

    Agapitov, O. V.; Artemyev, A. V.; Mourenas, D.; Mozer, F. S.; Krasnoselskikh, V.

    2015-01-01

    International audience; Simultaneous observations of electron velocity distributions and chorus waves by the Van Allen Probe B are analyzed to identify long-lasting (more than 6 h) signatures of electron Landau resonant interactions with oblique chorus waves in the outer radiation belt. Such Landau resonant interactions result in the trapping of ˜1-10 keV electrons and their acceleration up to 100-300 keV. This kind of process becomes important for oblique whistler mode waves having a signifi...

  17. The ATLAS Tau Trigger

    CERN Document Server

    Rados, PK; The ATLAS collaboration

    2014-01-01

    Physics processes involving tau leptons play a crucial role in understanding particle physics at the high energy frontier. The ability to efficiently trigger on events containing hadronic tau decays is therefore of particular importance to the ATLAS experiment. During the 2012 run, the Large Hadronic Collder (LHC) reached instantaneous luminosities of nearly $10^{34} cm^{-2}s^{-1}$ with bunch crossings occurring every $50 ns$. This resulted in a huge event rate and a high probability of overlapping interactions per bunch crossing (pile-up). With this in mind it was necessary to design an ATLAS tau trigger system that could reduce the event rate to a manageable level, while efficiently extracting the most interesting physics events in a pile-up robust manner. In this poster the ATLAS tau trigger is described, its performance during 2012 is presented, and the outlook for the LHC Run II is briefly summarized.

  18. Microfabricated triggered vacuum switch

    Science.gov (United States)

    Roesler, Alexander W [Tijeras, NM; Schare, Joshua M [Albuquerque, NM; Bunch, Kyle [Albuquerque, NM

    2010-05-11

    A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

  19. Some unusual discrete VLF emissions observed at a low-latitude ground station at Agra

    Directory of Open Access Journals (Sweden)

    B. Singh

    Full Text Available A detailed analysis of the VLF emissions data obtained during occasional whistler campaigns at the low-latitude ground station Agra (geomagnetic latitude 17°1' N, L = 1.15 has yielded some unusual discrete VLF emissions of the rising type. These include (1 emissions occurring at time intervals increasing in ge ommetrical progression, (2 emissions occuring simulta neously in different frequency ranges and (3 emissions observed during daytime. In the present study, the observed characteristics of these emissions are described and interpreted. It is shown that the increasing time delay between different components of the emissions match closely with the propagation time delays between different hops of a whistler of dispersion 19 s1/2, the unusual occurrence of the emissions in two different frequency ranges approximately at the same time may possibly be linked with their generation at two different locations, and the occurrence of emissions during daytime may be due to propagation under the influence of equatorial anomaly.

  20. Some unusual discrete VLF emissions observed at a low-latitude ground station at Agra

    Directory of Open Access Journals (Sweden)

    B. Singh

    1997-08-01

    Full Text Available A detailed analysis of the VLF emissions data obtained during occasional whistler campaigns at the low-latitude ground station Agra (geomagnetic latitude 17°1' N, L = 1.15 has yielded some unusual discrete VLF emissions of the rising type. These include (1 emissions occurring at time intervals increasing in ge ommetrical progression, (2 emissions occuring simulta neously in different frequency ranges and (3 emissions observed during daytime. In the present study, the observed characteristics of these emissions are described and interpreted. It is shown that the increasing time delay between different components of the emissions match closely with the propagation time delays between different hops of a whistler of dispersion 19 s1/2, the unusual occurrence of the emissions in two different frequency ranges approximately at the same time may possibly be linked with their generation at two different locations, and the occurrence of emissions during daytime may be due to propagation under the influence of equatorial anomaly.

  1. Trigger and decision processors

    International Nuclear Information System (INIS)

    Franke, G.

    1980-11-01

    In recent years there have been many attempts in high energy physics to make trigger and decision processes faster and more sophisticated. This became necessary due to a permanent increase of the number of sensitive detector elements in wire chambers and calorimeters, and in fact it was possible because of the fast developments in integrated circuits technique. In this paper the present situation will be reviewed. The discussion will be mainly focussed upon event filtering by pure software methods and - rather hardware related - microprogrammable processors as well as random access memory triggers. (orig.)

  2. ALICE High Level Trigger

    CERN Multimedia

    Alt, T

    2013-01-01

    The ALICE High Level Trigger (HLT) is a computing farm designed and build for the real-time, online processing of the raw data produced by the ALICE detectors. Events are fully reconstructed from the raw data, analyzed and compressed. The analysis summary together with the compressed data and a trigger decision is sent to the DAQ. In addition the reconstruction of the events allows for on-line monitoring of physical observables and this information is provided to the Data Quality Monitor (DQM). The HLT can process event rates of up to 2 kHz for proton-proton and 200 Hz for Pb-Pb central collisions.

  3. Aftershocks and triggering processes in rock fracture

    Science.gov (United States)

    Davidsen, J.; Kwiatek, G.; Goebel, T.; Stanchits, S. A.; Dresen, G.

    2017-12-01

    One of the hallmarks of our understanding of seismicity in nature is the importance of triggering processes, which makes the forecasting of seismic activity feasible. These triggering processes by which one earthquake induces (dynamic or static) stress changes leading to potentially multiple other earthquakes are at the core relaxation processes. A specic example of triggering are aftershocks following a large earthquake, which have been observed to follow certain empirical relationships such as the Omori-Utsu relation. Such an empirical relation should arise from the underlying microscopic dynamics of the involved physical processes but the exact connection remains to be established. Simple explanations have been proposed but their general applicability is unclear. Many explanations involve the picture of an earthquake as a purely frictional sliding event. Here, we present experimental evidence that these empirical relationships are not limited to frictional processes but also arise in fracture zone formation and are mostly related to compaction-type events. Our analysis is based on tri-axial compression experiments under constant displacement rate on sandstone and granite samples using spatially located acoustic emission events and their focal mechanisms. More importantly, we show that event-event triggering plays an important role in the presence of large-scale or macrocopic imperfections while such triggering is basically absent if no signicant imperfections are present. We also show that spatial localization and an increase in activity rates close to failure do not necessarily imply triggering behavior associated with aftershocks. Only if a macroscopic crack is formed and its propagation remains subcritical do we observe significant triggering.

  4. Triggering in Thermoacoustics

    Directory of Open Access Journals (Sweden)

    Matthew P. Juniper

    2012-09-01

    Full Text Available Under certain conditions, the flow in a combustion chamber can sustain large amplitude oscillations even when its steady state is linearly stable. Experimental studies show that these large oscillations can sometimes be triggered by very low levels of background noise. This theoretical paper sets out the conditions that are necessary for triggering to occur. It uses a weakly nonlinear analysis to show when these conditions will be satisfied for cases where the heat release rate is a function of the acoustic velocity. The role played by non-normality is investigated. It is shown that, when a state triggers to sustained oscillations from the lowest possible energy, it exploits transient energy growth around an unstable limit cycle. The positions of these limit cycles in state space is determined by nonlinearity, but the tangled-ness of trajectories in state space is determined by non-normality. When viewed in this dynamical systems framework, triggering in thermoacoustics is seen to be directly analogous to bypass transition to turbulence in pipe flow.

  5. Solated Muon Trigger

    CERN Document Server

    Albajar, Carmen

    2000-01-01

    An Isolated Muon L1 Trigger is proposed to reject muons from decays of b and c-quarks preserving high efficiency for muons from heavier objects. It is shown that the proposed algorithm is feasible and significant rejection factor ( 3-10) can be achieved. Similar algorithm can be applied at L2.

  6. Dealing with Asthma Triggers

    Science.gov (United States)

    ... one trigger that you shouldn't avoid because exercise is important for your health. Your doctor will want you to be active, so talk with him or her about what to do before playing ... or 15 minutes before you exercise or play sports. And, of course, you'll ...

  7. Emission of nonlinear whistler waves at the front of perpendicular supercritical shocks: Hybrid versus full particle simulations

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Trávníček, Pavel; Lembège, B.; Savoini, P.

    2007-01-01

    Roč. 34, č. 14 (2007), L14109/1-L14109/5 ISSN 0094-8276 R&D Projects: GA AV ČR IAA300420702; GA AV ČR IAA300420602 Institutional research plan: CEZ:AV0Z30420517 Keywords : collisionless shocks * self-reformation * wave-particle interaction Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.744, year: 2007

  8. The ATLAS Tau Trigger

    International Nuclear Information System (INIS)

    Rados, Petar Kevin

    2013-06-01

    The tau lepton plays a crucial role in understanding particle physics at the Tera scale. One of the most promising probes of the Higgs boson coupling to fermions is with detector signatures involving taus. In addition, many theories beyond the Standard Model, such as supersymmetry and exotic particles (W' and Z'), predict new physics with large couplings to taus. The ability to trigger on hadronic tau decays is therefore critical to achieving the physics goals of the ATLAS experiment. The higher instantaneous luminosities of proton-proton collisions achieved by the Large Hadron Collider (LHC) in 2012 resulted in a larger probability of overlap (pile-up) between bunch crossings, and so it was critical for ATLAS to have an effective tau trigger strategy. The details of this strategy are summarized in this paper, and the results of the latest performance measurements are presented. (authors)

  9. Minimum risk trigger indices

    International Nuclear Information System (INIS)

    Tingey, F.H.

    1979-01-01

    A viable safeguards system includes among other things the development and use of indices which trigger various courses of action. The usual limit of error calculation provides such an index. The classical approach is one of constructing tests which, under certain assumptions, make the likelihood of a false alarm small. Of concern also is the test's failure to indicate a loss (diversion) when in fact one has occurred. Since false alarms are usually costly and losses both costly and of extreme strategic sinificance, there remains the task of balancing the probability of false alarm and its consequences against the probability of undetected loss and its consequences. The application of other than classical hypothesis testing procedures are considered in this paper. Using various consequence models, trigger indices are derived which have certain optimum properties. Application of the techniques would enhance the material control function

  10. The LPS trigger system

    International Nuclear Information System (INIS)

    Benotto, F.; Costa, M.; Staiano, A.; Zampieri, A.; Bollito, M.; Isoardi, P.; Pernigotti, E.; Sacchi, R.; Trapani, P.P.; Larsen, H.; Massam, T.; Nemoz, C.

    1996-03-01

    The Leading Proton Spectrometer (LPS) has been equipped with microstrip silicon detectors specially designed to trigger events with high values of x L vertical stroke anti p' p vertical stroke / vertical stroke anti p p vertical stroke ≥0.95 where vertical stroke anti p' p vertical stroke and vertical stroke anti p p vertical stroke are respectively the momenta of outgoing and incoming protons. The LPS First Level Trigger can provide a clear tag for very high momentum protons in a kinematical region never explored before. In the following we discuss the physics motivation in tagging very forward protons and present a detailed description of the detector design, the front end electronics, the readout electronics, the Monte Carlo simulation and some preliminary results from 1995 data taking. (orig.)

  11. GLAST's GBM Burst Trigger

    Science.gov (United States)

    Band, D.; Briggs, M.; Connaughton, V.; Kippen, M.; Preece, R.

    2003-01-01

    The GLAST Burst Monitor (GBM) will detect and localize bursts for the GLAST mission, and provide the spectral and temporal context in the traditional 10 keV to 25 MeV band for the high energy observations by the Large Area Telescope (LAT). The GBM will use traditional rate triggers in up to three energy bands, and on a variety of timescales between 16 ms and 16 s.

  12. The ARGUS vertex trigger

    International Nuclear Information System (INIS)

    Koch, N.; Kolander, M.; Kolanoski, H.; Siegmund, T.; Bergter, J.; Eckstein, P.; Schubert, K.R.; Waldi, R.; Imhof, M.; Ressing, D.; Weiss, U.; Weseler, S.

    1995-09-01

    A fast second level trigger has been developed for the ARGUS experiment which recognizes tracks originating from the interaction region. The processor compares the hits in the ARGUS Micro Vertex Drift Chamber to 245760 masks stored in random access memories. The masks which are fully defined in three dimensions are able to reject tracks originating in the wall of the narrow beampipe of 10.5 mm radius. (orig.)

  13. Neural networks for triggering

    International Nuclear Information System (INIS)

    Denby, B.; Campbell, M.; Bedeschi, F.; Chriss, N.; Bowers, C.; Nesti, F.

    1990-01-01

    Two types of neural network beauty trigger architectures, based on identification of electrons in jets and recognition of secondary vertices, have been simulated in the environment of the Fermilab CDF experiment. The efficiencies for B's and rejection of background obtained are encouraging. If hardware tests are successful, the electron identification architecture will be tested in the 1991 run of CDF. 10 refs., 5 figs., 1 tab

  14. Physics issues on triggering

    Indian Academy of Sciences (India)

    The detector at the international linear collider (ILC) should be able to run 'trig- gerless' which means that all events can be read out and then be analysed with the offline reconstruction program in a trigger farm. The event rates for 'high Q2' events like W-pairs or q¯q are low, about 0.1/train. However, there is a significant.

  15. Noise and trigger efficiency characterization of cooled silicon pad detectors

    CERN Document Server

    Marques, A C; Correia, J G; Silva, M R; Rudge, A; Weilhammer, P; Soares, J C

    2007-01-01

    Technical progress on silicon pad electron detectors, currently used in emission channelling experiments to study lattice location of radioactive dopants and impurities in single crystals, is reported. Noise and trigger efficiency improvements are achieved by using 500 μm and 1 mm thick detectors coupled to a cooled readout system. The static properties, noise, gamma ray and electron trigger efficiency and energy resolution for different temperatures under air and vacuum were measured. The advantages of the future implementation of 1 mm silicon pad detectors with cooled self-triggering readout chips are discussed.

  16. Probability of relativistic electron trapping by parallel and oblique whistler-mode waves in Earth's radiation belts

    Energy Technology Data Exchange (ETDEWEB)

    Artemyev, A. V., E-mail: ante0226@gmail.com; Vasiliev, A. A.; Neishtadt, A. I. [Space Research Institute, RAS, Moscow, Russia, 117997 (Russian Federation); Mourenas, D.; Krasnoselskikh, V. [LPC2E/CNRS—University of Orleans, 3A, Avenue de la Recherche Scientifique, F-45071 Orleans Cedex (France); Agapitov, O. V. [Space Sciences Laboratory, University of California, Berkeley, California 94720 (United States)

    2015-11-15

    We investigate electron trapping by high-amplitude whistler-mode waves propagating at small as well as large angles relative to geomagnetic field lines. The inhomogeneity of the background magnetic field can result in an effective acceleration of trapped particles. Here, we derive useful analytical expressions for the probability of electron trapping by both parallel and oblique waves, paving the way for a full analytical description of trapping effects on the particle distribution. Numerical integrations of particle trajectories allow to demonstrate the accuracy of the derived analytical estimates. For realistic wave amplitudes, the levels of probabilities of trapping are generally comparable for oblique and parallel waves, but they turn out to be most efficient over complementary energy ranges. Trapping acceleration of <100 keV electrons is mainly provided by oblique waves, while parallel waves are responsible for the trapping acceleration of >100 keV electrons.

  17. ATLAS Tau Trigger

    CERN Document Server

    Belanger-Champagne, C; Bosman, M; Brenner, R; Casado, MP; Czyczula, Z; Dam, M; Demers, S; Farrington, S; Igonkina, O; Kalinowski, A; Kanaya, N; Osuna, C; Pérez, E; Ptacek, E; Reinsch, A; Saavedra, A; Sopczak, A; Strom, D; Torrence, E; Tsuno, S; Vorwerk, V; Watson, A; Xella, S

    2008-01-01

    Moving to the high energy scale of the LHC, the identification of tau leptons will become a necessary and very powerful tool, allowing a discovery of physics beyond Standard Model. Many models, among them light SM Higgs and various SUSY models, predict an abundant production of taus with respect to other leptons. The reconstruction of hadronic tau decays, although a very challenging task in hadronic enviroments, allows to increase a signal efficiency by at least of factor 2, and provides an independent control sample to disantangle lepton tau decays from prompt electrons and muons. Thanks to the advanced calorimetry and tracking, the ATLAS experiment has developed tools to efficiently identify hadronic taus at the trigger level. In this presentation we will review the characteristics of taus and the methods to suppress low-multiplicity, low-energy jets contributions as well as we will address the tau trigger chain which provide a rejection rate of 10^5. We will further present plans for commissioning the ATLA...

  18. The D0 calorimeter trigger

    International Nuclear Information System (INIS)

    Guida, J.

    1992-12-01

    The D0 calorimeter trigger system consists of many levels to make physics motivated trigger decisions. The Level-1 trigger uses hardware techniques to reduce the trigger rate from ∼ 100kHz to 200Hz. It forms sums of electromagnetic and hadronic energy, globally and in towers, along with finding the missing transverse energy. A minimum energy is set on these energy sums to pass the event. The Level-2 trigger is a set of software filters, operating in a parallel-processing microvax farm which further reduces the trigger rate to a few Hertz. These filters will reject events which lack electron candidates, jet candidates, or missing transverse energy in the event. The performance of these triggers during the early running of the D0 detector will also be discussed

  19. Minimum Bias Trigger in ATLAS

    CERN Document Server

    Kwee, R E; The ATLAS collaboration

    2010-01-01

    Since the restart of the LHC in November 2009, ATLAS has collected inelastic pp-collisions to perform first measurements on charged particle densities. These measurements will help to constrain various models describing phenomenologically soft parton interactions. Understanding the trigger efficiencies for different event types are therefore crucial to minimize any possible bias in the event selection. ATLAS uses two main minimum bias triggers, featuring complementary detector components and trigger levels. While a hardware based first trigger level situated in the forward regions with 2.09 < |eta| < 3.8 has been proven to select pp-collisions very efficiently, the Inner Detector based minimum bias trigger uses a random seed on filled bunches and central tracking detectors for the event selection. Both triggers were essential for the analysis of kinematic spectra of charged particles. Their performance and trigger efficiency measurements as well as studies on possible bias sources will be presen...

  20. Cascade and Dissipation of Solar Wind Turbulence at Electron Scales: Whistlers or Kinetic Alfv\\'en Waves?

    Science.gov (United States)

    Sahraoui, Fouad; Goldstein, Melvyn L.

    2010-01-01

    Over the past few decades, large-scales solar wind (SW) turbulence has been studied extensively, both theoretically and observationally. Observed power spectra of the low frequency turbulence, which can be described in the magnetohydrodynamic (MHD) limit, are shown to obey the Kolmogorov scaling, $k"{ -5/3 }$, down the local proton gyrofrequency ($C{ci} \\sim O.l$-Hz). Turbulence at frequencies above $C{ci}$ has not been thoroughly investigated and remains far less well understood. Above $C{ ci}$ the spectrum steepens to $\\sim f"{ -2.5}$ and a debate exists as to whether the turbulence has become dominated by dispersive kinetic Alfven waves (KA W) or by whistler waves, before it is dissipated at small scales, In a case study Sahraoui et al., PRL (2009) have reported the first direct determination of the dissipation range of solar wind turbulence near the electron gyroscale using the high resolution Cluster magnetic and electric field data (up to $10"2$-Hz in the spacecraft reference frame). Above the Doppler-shifted proton scale $C{\\rho i}$ a new inertial range with a scaling $\\sim f"{ -2.3}$ has been evidenced and shown to remarkably agree with theoretical predictions of a quasi-two-dimensional cascade into KA W turbulence. Here, we use a wider sample of data sets of small scale SW turbulence under different plasma conditions, and investigate under which physical criteria the KA W (or the whistler) turbulence may be observed to carry out the cascade at small scales, These new observations/criteria are compared to the predictions on the cascade and the (kinetic) dissipation from the Vlasov theory. Implications of the results on the heating problem of the solar wind will be discussed.

  1. Triggering at high luminosity: fake triggers from pile-up

    International Nuclear Information System (INIS)

    Johnson, R.

    1983-01-01

    Triggers based on a cut in transverse momentum (p/sub t/) have proved to be useful in high energy physics both because they indicte that a hard constituent scattering has occurred and because they can be made quickly enough to gate electronics. These triggers will continue to be useful at high luminosities if overlapping events do not cause an excessive number of fake triggers. In this paper, I determine if this is indeed a problem at high luminosity machines

  2. Nostalgia: content, triggers, functions.

    Science.gov (United States)

    Wildschut, Tim; Sedikides, Constantine; Arndt, Jamie; Routledge, Clay

    2006-11-01

    Seven methodologically diverse studies addressed 3 fundamental questions about nostalgia. Studies 1 and 2 examined the content of nostalgic experiences. Descriptions of nostalgic experiences typically featured the self as a protagonist in interactions with close others (e.g., friends) or in momentous events (e.g., weddings). Also, the descriptions contained more expressions of positive than negative affect and often depicted the redemption of negative life scenes by subsequent triumphs. Studies 3 and 4 examined triggers of nostalgia and revealed that nostalgia occurs in response to negative mood and the discrete affective state of loneliness. Studies 5, 6, and 7 investigated the functional utility of nostalgia and established that nostalgia bolsters social bonds, increases positive self-regard, and generates positive affect. These findings demarcate key landmarks in the hitherto uncharted research domain of nostalgia.

  3. Latent myofascial trigger points.

    Science.gov (United States)

    Ge, Hong-You; Arendt-Nielsen, Lars

    2011-10-01

    A latent myofascial trigger point (MTP) is defined as a focus of hyperirritability in a muscle taut band that is clinically associated with local twitch response and tenderness and/or referred pain upon manual examination. Current evidence suggests that the temporal profile of the spontaneous electrical activity at an MTP is similar to focal muscle fiber contraction and/or muscle cramp potentials, which contribute significantly to the induction of local tenderness and pain and motor dysfunctions. This review highlights the potential mechanisms underlying the sensory-motor dysfunctions associated with latent MTPs and discusses the contribution of central sensitization associated with latent MTPs and the MTP network to the spatial propagation of pain and motor dysfunctions. Treating latent MTPs in patients with musculoskeletal pain may not only decrease pain sensitivity and improve motor functions, but also prevent latent MTPs from transforming into active MTPs, and hence, prevent the development of myofascial pain syndrome.

  4. ATLAS trigger: Design and commissioning

    Science.gov (United States)

    Pastore, F.; Atlas Collaboration

    2012-12-01

    The ATLAS detector at CERN's Large Hadron Collider (LHC) will be exposed to proton-proton collisions from beams crossing at 40 MHz. A three-level trigger system was designed to select potentially interesting events and reduce the incoming rate to 100-200 Hz. The first trigger level (LVL1) is implemented in custom-built electronics, the second and third trigger levels are realised in software. The trigger system and its design parameters will be described with focus on computing and data aquision challenges. The results from both commissioning cosmic runs and first experiences from the LHC beam in 2008 will be overviewed. These running periods allowed us to exercise the trigger system online, including its configuration and monitoring infrastructure, as well as reconstruction and selection algorithms. The details on the plans for commissioning the ATLAS trigger when the LHC starts operations will be presented.

  5. Flexible trigger menu implementation on the Global Trigger for the CMS Level-1 trigger upgrade

    Science.gov (United States)

    MATSUSHITA, Takashi; CMS Collaboration

    2017-10-01

    The CMS experiment at the Large Hadron Collider (LHC) has continued to explore physics at the high-energy frontier in 2016. The integrated luminosity delivered by the LHC in 2016 was 41 fb‑1 with a peak luminosity of 1.5 × 1034 cm‑2s‑1 and peak mean pile-up of about 50, all exceeding the initial estimations for 2016. The CMS experiment has upgraded its hardware-based Level-1 trigger system to maintain its performance for new physics searches and precision measurements at high luminosities. The Global Trigger is the final step of the CMS Level-1 trigger and implements a trigger menu, a set of selection requirements applied to the final list of objects from calorimeter and muon triggers, for reducing the 40 MHz collision rate to 100 kHz. The Global Trigger has been upgraded with state-of-the-art FPGA processors on Advanced Mezzanine Cards with optical links running at 10 GHz in a MicroTCA crate. The powerful processing resources of the upgraded system enable implementation of more algorithms at a time than previously possible, allowing CMS to be more flexible in how it handles the available trigger bandwidth. Algorithms for a trigger menu, including topological requirements on multi-objects, can be realised in the Global Trigger using the newly developed trigger menu specification grammar. Analysis-like trigger algorithms can be represented in an intuitive manner and the algorithms are translated to corresponding VHDL code blocks to build a firmware. The grammar can be extended in future as the needs arise. The experience of implementing trigger menus on the upgraded Global Trigger system will be presented.

  6. Myofascial Trigger Point Pain Syndromes.

    Science.gov (United States)

    Gerwin, Robert D

    2016-10-01

    Myofascial pain syndromes caused by trigger points (TrPs) in muscle are a common cause of local and generalized pain. Trigger points are hyperirritable zones in contracted bands of muscle, thought to be caused by muscle overload or stress. Stress TrPs have characteristic electromyographic features, and can be visualized with ultrasound and magnetic resonance elastography. Trigger point needling or injection can be effective in inactivating TrP, but correcting triggers is also critical. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  7. Intense Harmonic Emissions Observed in Saturn's Ionosphere

    Science.gov (United States)

    Sulaiman, A. H.; Kurth, W. S.; Persoon, A. M.; Menietti, J. D.; Farrell, W. M.; Ye, S.-Y.; Hospodarsky, G. B.; Gurnett, D. A.; Hadid, L. Z.

    2017-12-01

    The Cassini spacecraft's first Grand Finale orbit was carried out in April 2017. This set of 22 orbits had an inclination of 63° with a periapsis grazing Saturn's ionosphere, thus providing unprecedented coverage and proximity to the planet. Cassini's Radio and Plasma Wave Science instrument repeatedly detected intense electrostatic waves and their harmonics near closest approach in the dayside equatorial topside ionosphere. The fundamental modes were found to both scale and trend best with the H+ plasma or lower hybrid frequencies, depending on the plasma composition considered. The fine-structured harmonics are unlike previous observations, which scale with cyclotron frequencies. We explore their generation mechanism and show strong evidence of their association with whistler mode waves, consistent with theory. The possibility of Cassini's presence in the ionosphere influencing the resonance and harmonics is discussed. Given their link to the lower hybrid frequency, these emissions may offer clues to constraining Saturn's ionospheric properties.

  8. Using the cold plasma dispersion relation and whistler mode waves to quantify the antenna sheath impedance of the Van Allen Probes EFW instrument

    Czech Academy of Sciences Publication Activity Database

    Hartley, D. P.; Kletzing, C. A.; Kurth, W. S.; Bounds, S. R.; Averkamp, T. F.; Hospodarsky, G. B.; Wygant, J. R.; Bonnell, J. W.; Santolík, Ondřej; Watt, C. E. J.

    2016-01-01

    Roč. 121, č. 5 (2016), s. 4590-4606 ISSN 2169-9380 R&D Projects: GA MŠk(CZ) LH15304 Institutional support: RVO:68378289 Keywords : EFW * EMFISIS * plasmaspheric hiss * sheath impedance * Van Allen Probes * whistler mode chorus Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.733, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2016JA022501/abstract

  9. Thermally activated trigger device

    International Nuclear Information System (INIS)

    Harty, R.B.; Camaret, T.L.

    1988-01-01

    This patent describes a nuclear space reactor, a thermally activated trigger device for rendering the reactor subcritical upon reentry to the earth's atmosphere, the device comprising: a closed vessel, a piston slideably mounted in the vessel to divide it into first and second compartments, an inert gas contained within each of the compartments at substantially the same pressure, a connecting rod operatively connected to the piston and to actuator means, the actuator means providing for moving means for rendering the reactor subcritical upon movement of the connecting rod; a bellows having opposite ends, one of the ends being affixed to and in sealing engagement with the connecting rod and the other of the ends being affixed to and in sealing engagement with the vessel for permitting linear movement of the connecting rod and preventing any escape of the inert gas from the closed vessel; and normally closed pipes communicating with one of the compartments for venting the inert gas therefrom when any of the pipes is open, the pipes being located at different parts of the nuclear space reactor so that the closed ends thereof are exposed to the atmosphere upon reentry of the reactor to the atmosphere. The pipes are designed to open at a selected temperature resulting from the reentry so that the gas leaves the communicating compartment via an open pipe to cause a difference in pressure between the compartments sufficient for the higher pressure in the other compartment to move the piston and thereby activate the actuator means

  10. Trigger and data acquisition

    CERN Multimedia

    CERN. Geneva; Gaspar, C

    2001-01-01

    Past LEP experiments generate data at 0.5 MByte/s from particle detectors with over a quarter of a million readout channels. The process of reading out the electronic channels, treating them, and storing the date produced by each collision for further analysis by the physicists is called "Data Acquisition". Not all beam crossings produce interesting physics "events", picking the interesting ones is the task of the "Trigger" system. In order to make sure that the data is collected in good conditions the experiment's operation has to be constantly verified. In all, at LEP experiments over 100 000 parameters were monitored, controlled, and synchronized by the "Monotoring and control" system. In the future, LHC experiments will produce as much data in a single day as a LEP detector did in a full year's running with a raw data rate of 10 - 100 MBytes/s and will have to cope with some 800 million proton-proton collisions a second of these collisions only one in 100 million million is interesting for new particle se...

  11. The TOTEM modular trigger system

    Energy Technology Data Exchange (ETDEWEB)

    Bagliesi, M.G., E-mail: mg.bagliesi@pi.infn.i [University of Siena and INFN Pisa (Italy); Berretti, M.; Cecchi, R.; Greco, V.; Lami, S.; Latino, G.; Oliveri, E.; Pedreschi, E.; Scribano, A.; Spinella, F.; Turini, N. [University of Siena and INFN Pisa (Italy)

    2010-05-21

    The TOTEM experiment will measure the total cross-section with the luminosity independent method and study elastic and diffractive scattering at the LHC. We are developing a modular trigger system, based on programmable logic, that will select meaningful events within 2.5{mu}s. The trigger algorithm is based on a tree structure in order to obtain information compression. The trigger primitive is generated directly on the readout chip, VFAT, that has a specific fast output that gives low resolution hits information. In two of the TOTEM detectors, Roman Pots and T2, a coincidence chip will perform track recognition directly on the detector readout boards, while for T1 the hits are transferred from the VFATs to the trigger hardware. Starting from more than 2000 bits delivered by the detector electronics, we extract, in a first step, six trigger patterns of 32 LVDS signals each; we build, then, on a dedicated board, a 1-bit (L1) trigger signal for the TOTEM experiment and 16 trigger bits to the CMS experiment global trigger system for future common data taking.

  12. The TOTEM modular trigger system

    International Nuclear Information System (INIS)

    Bagliesi, M.G.; Berretti, M.; Cecchi, R.; Greco, V.; Lami, S.; Latino, G.; Oliveri, E.; Pedreschi, E.; Scribano, A.; Spinella, F.; Turini, N.

    2010-01-01

    The TOTEM experiment will measure the total cross-section with the luminosity independent method and study elastic and diffractive scattering at the LHC. We are developing a modular trigger system, based on programmable logic, that will select meaningful events within 2.5μs. The trigger algorithm is based on a tree structure in order to obtain information compression. The trigger primitive is generated directly on the readout chip, VFAT, that has a specific fast output that gives low resolution hits information. In two of the TOTEM detectors, Roman Pots and T2, a coincidence chip will perform track recognition directly on the detector readout boards, while for T1 the hits are transferred from the VFATs to the trigger hardware. Starting from more than 2000 bits delivered by the detector electronics, we extract, in a first step, six trigger patterns of 32 LVDS signals each; we build, then, on a dedicated board, a 1-bit (L1) trigger signal for the TOTEM experiment and 16 trigger bits to the CMS experiment global trigger system for future common data taking.

  13. Upgrade trigger: Biannual performance update

    CERN Document Server

    Aaij, Roel; Couturier, Ben; Esen, Sevda; De Cian, Michel; De Vries, Jacco Andreas; Dziurda, Agnieszka; Fitzpatrick, Conor; Fontana, Marianna; Grillo, Lucia; Hasse, Christoph; Jones, Christopher Rob; Le Gac, Renaud; Matev, Rosen; Neufeld, Niko; Nikodem, Thomas; Polci, Francesco; Del Buono, Luigi; Quagliani, Renato; Schwemmer, Rainer; Seyfert, Paul; Stahl, Sascha; Szumlak, Tomasz; Vesterinen, Mika Anton; Wanczyk, Joanna; Williams, Mark Richard James; Yin, Hang; Zacharjasz, Emilia Anna

    2017-01-01

    This document presents the performance of the LHCb Upgrade trigger reconstruction sequence, incorporating changes to the underlying reconstruction algorithms and detector description since the Trigger and Online Upgrade TDR. An updated extrapolation is presented using the most recent example of an Event Filter Farm node.

  14. A survey of Galileo plasma wave instrument observations of Jovian whistler-mode chorus

    Directory of Open Access Journals (Sweden)

    J. D. Menietti

    2008-07-01

    Full Text Available A survey of plasma wave observations at Jupiter obtained by the plasma wave instrument on board the Galileo spacecraft is presented. The observations indicate that chorus emissions are observed commonly in the Jovian magnetosphere near the magnetic equator in the approximate radial range 6emissions are somewhat more intense on the dayside, but this may be a result of insufficient nightside observations. The orbit of Galileo is also restricted to ±3° of the Jovigraphic equator, but the tilt of the magnetic field permits coverage of a range of magnetic latitudes of −13°<λmag<+13°. The similarities of chorus emissions to terrestrial observations are a good reason to speculate that Jovian chorus emission may play a significant role in the stochastic acceleration of electrons in the radial range 6–10 RJ as recent studies indicate. These electrons may then be transported inward by radial diffusion where they are additionally accelerated to form the synchrotron radiation belt source.

  15. A survey of Galileo plasma wave instrument observations of Jovian whistler-mode chorus

    Directory of Open Access Journals (Sweden)

    J. D. Menietti

    2008-07-01

    Full Text Available A survey of plasma wave observations at Jupiter obtained by the plasma wave instrument on board the Galileo spacecraft is presented. The observations indicate that chorus emissions are observed commonly in the Jovian magnetosphere near the magnetic equator in the approximate radial range 6<r<10 RJ. The survey includes almost all local times but not equally sampled in radial distance due to the spacecraft trajectory. The data suggest that chorus emissions are somewhat more intense on the dayside, but this may be a result of insufficient nightside observations. The orbit of Galileo is also restricted to ±3° of the Jovigraphic equator, but the tilt of the magnetic field permits coverage of a range of magnetic latitudes of −13°<λmag<+13°. The similarities of chorus emissions to terrestrial observations are a good reason to speculate that Jovian chorus emission may play a significant role in the stochastic acceleration of electrons in the radial range 6–10 RJ as recent studies indicate. These electrons may then be transported inward by radial diffusion where they are additionally accelerated to form the synchrotron radiation belt source.

  16. DUMAND data acquisition with triggering

    International Nuclear Information System (INIS)

    Brenner, A.E.; Theriot, D.; March, R.H.

    1980-01-01

    A data acquisition scheme for the standard DUMAND array that includes a simple triggering scheme as a fundamental part of the system is presented. Although there are a number of not yet fully understood parameters, it is assumed that thresholds can be set in such a manner as to give rise to a triggered signal that is not so dominated by randoms that it gives a substantial decrease in the data acquisition rate over that which would be required by a nontriggered system. It is also assumed that the triggering logic is relatively simple and does not need major computational capabilities for a trigger logic decision. With these assumptions, it is possible to generate the trigger at the array and restrict the data transfer to shore. However, with a not unreasonable delay of 200 microseconds, it is even possible to transmit the information for the trigger to shore and perform all that logic on the shore. The critical point is to send the minimum amount of information necessary to construct the trigger such that one need not send all the possible information in all detectors of the array continuously to shore. 1 figure

  17. ATLAS Trigger: design and commissioning

    CERN Document Server

    Pastore, F; The ATLAS collaboration

    2009-01-01

    The ATLAS detector at CERN's Large Hadron Collider (LHC) will be exposed to proton-proton collisions from beams crossing at 40 MHz. A three-level trigger system was designed to select potentially interesting events and reduce the incoming rate to 100-200 Hz. The first trigger level (LVL1) is implemented in custom-built electronics, the second and third trigger levels are realised in software. Based on calorimeter information and hits in dedicated muon-trigger detectors, the LVL1 decision is made by the central-trigger processor yielding an output rate of less than 100 kHz. The allowed latency for the trigger decision at this stage is less than 2.5 micro seconds. The two subsequent levels, called, High-Level Trigger (HLT) further reduce the rate to the offline storage rate while retaining the most interesting physics. The HLT is implemented in software running in commercially available computer farms and consists of Level 2 and Event Filter. To reduce the network data traffic and the processing time to managea...

  18. The ATLAS Missing ET trigger

    CERN Document Server

    Beauchemin, P; The ATLAS collaboration

    2010-01-01

    Over the last few months, the ATLAS detector collected 900 GeV LHC collision events which allowed for the study the performance of the ATLAS Trigger and Data Acquisition system (TDAQ). With the 7 TeV collision data collected recently, the performance studies of the trigger system are critical for a successful physics program. In particular a large spectrum of physics results will rely on the capacity of the ATLAS TDAQ system to collect events based on the estimate of the missing transverse energy (MET) contained in each event. The MET trigger would be, for example, the primary trigger to be used in new physics searches for processes involving new weakly interacting particles, which could account for the astronomically observed dark matter. In addition to discovery perspectives, the MET trigger can also be used in combination with other triggers to control the rate of signatures involving low energy objects. For example, the MET trigger is necessary in order to measure non-boosted W in the tau channel. Finally...

  19. An ultrafast nanotip electron gun triggered by grating-coupled surface plasmons

    Energy Technology Data Exchange (ETDEWEB)

    Schröder, Benjamin; Sivis, Murat; Bormann, Reiner; Schäfer, Sascha; Ropers, Claus, E-mail: cropers@gwdg.de [4th Physical Institute - Solids and Nanostructures, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany)

    2015-12-07

    We demonstrate multiphoton photoelectron emission from gold nanotips induced by nanofocusing surface plasmons, resonantly excited on the tip shaft by a grating coupler. The tip is integrated into an electron gun assembly, which facilitates control over the spatial emission sites and allows us to disentangle direct grating emission from plasmon-triggered apex emission. The nanoscale source size of this electron gun concept enables highly coherent electron pulses with applications in ultrafast electron imaging and diffraction.

  20. Triggered Release from Polymer Capsules

    Energy Technology Data Exchange (ETDEWEB)

    Esser-Kahn, Aaron P. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry; Odom, Susan A. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry; Sottos, Nancy R. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Materials Science and Engineering; White, Scott R. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Aerospace Engineering; Moore, Jeffrey S. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry

    2011-07-06

    Stimuli-responsive capsules are of interest in drug delivery, fragrance release, food preservation, and self-healing materials. Many methods are used to trigger the release of encapsulated contents. Here we highlight mechanisms for the controlled release of encapsulated cargo that utilize chemical reactions occurring in solid polymeric shell walls. Triggering mechanisms responsible for covalent bond cleavage that result in the release of capsule contents include chemical, biological, light, thermal, magnetic, and electrical stimuli. We present methods for encapsulation and release, triggering methods, and mechanisms and conclude with our opinions on interesting obstacles for chemically induced activation with relevance for controlled release.

  1. Seismology: dynamic triggering of earthquakes.

    Science.gov (United States)

    Gomberg, Joan; Johnson, Paul

    2005-10-06

    After an earthquake, numerous smaller shocks are triggered over distances comparable to the dimensions of the mainshock fault rupture, although they are rare at larger distances. Here we analyse the scaling of dynamic deformations (the stresses and strains associated with seismic waves) with distance from, and magnitude of, their triggering earthquake, and show that they can cause further earthquakes at any distance if their amplitude exceeds several microstrain, regardless of their frequency content. These triggering requirements are remarkably similar to those measured in the laboratory for inducing dynamic elastic nonlinear behaviour, which suggests that the underlying physics is similar.

  2. ATLAS FTK: Fast Track Trigger

    CERN Document Server

    Amerio, S; The ATLAS collaboration; Andreazza, A; Annovi, A; Beretta, M; Bevacqua, V; Bogdan, M; Bossini, E; Boveia, A; Cavaliere, V; Canelli, F; Blazey, G; Cervigni, F; Cheng, Y; Citterio, M; Crescioli, F; Dell’Orso, M; Drake, G; Dunford, M; Giannetti, P; Giorgi, F; Hoff, J; Kapliy, A; Kasten, M; Kim, Y K; Kimura, N; Lanza, A; Liberali, V; Liu, T; Magalotti, D; McCarn, A; Melachrinos, C; Meroni, C; Negri, A; Neubauer, M; Penning, B; Piendibene, M; Proudfoot, J; Riva, M; Roda, C; Sabatini, F; Sacco, I; Shochet, M; Stabile, A; Tang, F; Tang, J; Tripiccione, R; Tuggle, J; Vercesi, V; Verzocchi, M; Villa, M; Vitillo, R A; Volpi, G; Webster, J; Wu, J; Yorita, K; Zhang, J

    2011-01-01

    A track reconstruction system for the trigger of the ATLAS detector at the Large Hadron Collider is described. The Fast Tracker is a highly parallel hardware system designed to operate at the Level-1 trigger output rate. It will provide high-quality tracks reconstructed over the entire inner detector by the start of processing in the Level-2 trigger. The system is based on associative memories for pattern recognition and fast FPGA’s for track reconstruction. Its design and expected performance under instantaneous luminosities up to 3 × 10^34/cm^2/s are discussed.

  3. Simulation and modeling of whistler-mode wave growth through cyclotron resonance with energetic electrons in the magnetosphere

    International Nuclear Information System (INIS)

    Carlson, C.R.

    1987-01-01

    New models and simulations of wave growth experienced by electromagnetic waves propagating through the magnetosphere in the whistler mode are presented. For these waves, which have frequencies below the electron gyro and plasma frequencies, the magnetospheric plasma acts like a natural amplifier often amplifying the waves by ∼ 30 dB. The mechanism for growth is cyclotron resonance between the circularly polarized waves and the gyrating energetic electrons which make up the Van Allen radiation belts. The main emphasis is to simulate single-frequency wave pulses, in the 2-6 kHz range, that have been injected into the magnetosphere, near L ∼ 4, by the Stanford transmitting facility at Siple station, Antarctica. However, the results can also be applied to naturally occurring signals, signals from other transmitters, non-CW signals, and signals in other parts of the magnetosphere not probed by the Siple Station transmitter. Results show the importance of the transient aspects in the wave-growth process. The wave growth established as the wave propagates toward the equator, is given a spatially advancing wave phase structure by the geomagnetic inhomogeneity. Through the feedback of this radiation upon other electrons, conditions are set up that results in the linearly increasing output frequency with time

  4. Climatic triggers for peatland initiation

    Science.gov (United States)

    Morris, Paul J.; Swindles, Graeme T.; Valdes, Paul J.; Ivanovic, Ruza F.; Gregoire, Lauren J.; Smith, Mark W.; Tarasov, Lev; Haywood, Alan M.; Bacon, Karen L.

    2017-04-01

    Peatlands are carbon-dense wetlands characterised by waterlogged, organic-rich soils. Modern-day peatlands have formed mainly since the Last Glacial Maximum (LGM), and despite covering only 3 % of the Earth's land surface are thought to store more than a third of all global soil carbon in the form of poorly decomposed plant detritus. Concern exists that this globally important carbon store may be vulnerable to near-future warming and changes in precipitation patterns, although the links between peatland development and climate are contested. The climatic and other environmental conditions that facilitate the initiation of peat are particularly poorly understood. We present the results of a novel, global study into the climate space of peat initiation since the LGM. We compiled a catalogue of radiocarbon dates of peat initiation from 942 sites that span a range of latitudes and biomes. We used the locations and ages of these peatlands to interrogate downscaled climate hindcasts at 500-yr intervals from a coupled atmosphere-ocean-vegetation general circulation model, HadCM3. This powerful combination of modelling and observational data provides a globally-consistent, temporally-extensive estimate of the climate spaces of peat initiation. In particular, it allows us to identify local and regional climatic changes that may have acted as triggers for peat formation. Peatlands in mid- and high-latitudes of both hemispheres, particularly in maritime locations, developed shortly after local increases in the time integral of growing season temperatures, and were seemingly not influenced by rainfall regime. Peat initiation at such sites appears to have been stimulated by temperature-driven increases in plant productivity in cold, postglacial landscapes, and was not water limited. The exception is the large peatland complex of the Western Siberian Lowlands, which was not glaciated during the last glacial period, and which appears to have been prompted instead by a strong

  5. Electron beam injection during active experiments. I - Electromagnetic wave emissions

    Science.gov (United States)

    Winglee, R. M.; Kellogg, P. J.

    1990-01-01

    The wave emissions produced in Echo 7 experiment by active injections of electron beams were investigated to determine the properties of the electromagnetic and electrostatic fields for both the field-aligned and cross-field injection in such experiments and to evaluate the sources of free energy and relative efficiencies for the generation of the VLF and HF emissions. It is shown that, for typical beam energies in active experiments, electromagnetic effects do not substantially change the bulk properties of the beam, spacecraft charging, and plasma particle acceleration. Through simulations, beam-generated whistlers; fundamental z-mode and harmonic x-mode radiation; and electrostatic electron-cyclotron, upper-hybrid, Langmuir, and lower-hybrid waves were identified. The characteristics of the observed wave spectra were found to be sensitive to both the ratio of the electron plasma frequency to the cyclotron frequency and the angle of injection relative to the magnetic field.

  6. The HLT inclusive B triggers

    CERN Document Server

    Gligorov, Vladimir V; Williams, Michael

    2011-01-01

    The inclusive HLT strategy relies on triggering any B decay based on two signatures: a single significantly displaced, high transverse momentum track, and a significantly displaced vertex containing this track and 1-3 other tracks, with high total transverse momentum. In order to provide optimal signal efficiency and background rejection the displaced vertex selection is implemented in a novel boosted decision tree algorithm incorporating information about the experimental resolution in the boosting procedure to protect against overtraining. The performance of these triggers has been commissioned using data taken during 2011 LHCb running and is evaluated here in a data-driven manner. The HLT inclusive triggers are found to have a rejection factor of around 1000 with respect to events selected by the L0 hardware trigger and a bbar purity close to 100%.

  7. GnRH agonist triggering

    DEFF Research Database (Denmark)

    Kol, Shahar; Humaidan, Peter; Al Humaidan, Peter Samir Heskjær

    2013-01-01

    The concept that a bolus of gonadotrophin-releasing hormone agonist (GnRHa) can replace human chorionic gonadotrophin (HCG) as a trigger of final oocyte maturation was introduced several years ago. Recent developments in the area strengthen this premise. GnRHa trigger offers important advantages......, including virtually complete prevention of ovarian hyperstimulation syndrome (OHSS), the introduction of a surge of FSH in addition to the LH surge and finally the possibility to individualize luteal-phase supplementation based on ovarian response to stimulation. We maintain that the automatic HCG...... triggering concept should be challenged and that the GnRHa trigger is the way to move forward with thoughtful consideration of the needs, safety and comfort of our patients. Routinely, human chorionic gonadotrophin (HCG) is used to induce ovulation in fertility treatments. This approach deviates...

  8. FERMIGTRIG - Fermi GBM Trigger Catalog

    Data.gov (United States)

    National Aeronautics and Space Administration — This table lists all of the triggers observed by one or more of the 14 GBM detectors (12 NaI and 2 BGO). Note that there are two Browse catalogs resulting from GBM...

  9. The CDF level-3 trigger

    International Nuclear Information System (INIS)

    Devlin, T.

    1993-01-01

    The Collider Detector at Fermilab (CDF) has been operating at the Tevatron and collecting data on proton-antiproton interactions with collision rates above 250,000 Hz. Three levels of filtering select events for data logging at a rate of about 4 Hz. The Level 3 trigger provides most of the capabilities of the offline production programs for event reconstruction and physics analysis. The type of physics triggers, application of cuts, and combinations of logical requirements for event selection are controlled at run time by a trigger table using a syntax fully integrated with the Level 1 and Level 2 hardware triggers. The level 3 software operates in 48 RISC/UNIX processors (over 1000 mips) served by four 20-MByte/sec data buses for input, output and control. The system architecture, debugging, code validation, error reporting, analysis capabilities and performance will be described

  10. B physics triggers at CMS

    CERN Document Server

    Starodumov, Andrei

    2003-01-01

    The CMS detector is mainly designed to investigate hard events. Only few Level-1 Trigger conditions are suitable to select soft B-meson decays. The B-physics potential of CMS depends strongly on a selection strategy at High-Level Trigger. The selection algorithms for some benchmark B-decay channels that allow CMS to perform competitive B-physics program are presented.

  11. Observations Directly Linking Relativistic Electron Microbursts to Whistler Mode Chorus: Van Allen Probes and FIREBIRD II

    Czech Academy of Sciences Publication Activity Database

    Breneman, A. W.; Crew, A.; Sample, J.; Klumpar, D.; Johnson, A.; Agapitov, O.; Shumko, M.; Turner, D. L.; Santolík, Ondřej; Wygant, J. R.; Cattell, C. A.; Thaller, S. A.; Blake, B.; Spence, H.; Kletzing, C. A.

    2017-01-01

    Roč. 44, č. 22 (2017), s. 11265-11272 ISSN 0094-8276 R&D Projects: GA ČR GA17-07027S Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : VLF-CHORUS * RADIATION BELT * ZONE ELECTRONS * SOURCE REGION * AURORAL-ZONE * GEM STORMS * PRECIPITATION * ASSOCIATION * RESOLUTION * EMISSIONS Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 4.253, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2017GL075001/epdf

  12. First observation of lion roar-like emissions in Saturn's magnetosheath

    Science.gov (United States)

    Pisa, David; Sulaiman, Ali H.; Santolik, Ondrej; Hospodarsky, George B.; Kurth, William S.; Gurnett, Donald A.

    2017-04-01

    Electromagnetic whistler mode waves known as "lion roars" have been reported by many missions inside the terrestrial magnetosheath. We show the observation of similar intense emissions in Saturn's magnetosheath as detected by the Cassini spacecraft. The emissions were observed inside the dawn sector (MLT˜0730) of the magnetosheath over a time period of nine hours before the satellite crossed the bow shock and entered the solar wind. The emissions were narrow-banded with a typical frequency of about 15 Hz well below the local electron cyclotron frequency (fce ˜100 Hz). Using the minimum variance analysis method, we show that the waves are right hand circularly polarized and propagate at small wave normal angles with respect to the ambient magnetic field. Here, for the first time, we report the evidence of lion roar-like emissions in Saturn's magnetosheath which represents a new and unique parameter regime.

  13. Flexible trigger menu implementation on the Global Trigger for the CMS Level-1 trigger upgrade

    CERN Document Server

    Matsushita, Takashi

    2017-01-01

    The CMS experiment at the Large Hadron Collider (LHC) has continued to explore physics at the high-energy frontier in 2016. The integrated luminosity delivered by the LHC in 2016 was 41~fb$^{-1}$ with a peak luminosity of 1.5 $\\times$ 10$^{34}$ cm$^{-2}$s$^{-1}$ and peak mean pile-up of about 50, all exceeding the initial estimations for 2016. The CMS experiment has upgraded its hardware-based Level-1 trigger system to maintain its performance for new physics searches and precision measurements at high luminosities. The Global Trigger is the final step of the CMS \\mbox{Level-1} trigger and implements a trigger menu, a set of selection requirements applied to the final list of objects from calorimeter and muon triggers, for reducing the 40 MHz collision rate to 100 kHz. The Global Trigger has been upgraded with state-of-the-art FPGA processors on Advanced Mezzanine Cards with optical links running at 10 GHz in a MicroTCA crate. The powerful processing resources of the upgraded system enable implemen...

  14. External triggering and triggered targeting strategies for drug delivery

    Science.gov (United States)

    Wang, Yanfei; Kohane, Daniel S.

    2017-06-01

    Drug delivery systems that are externally triggered to release drugs and/or target tissues hold considerable promise for improving the treatment of many diseases by minimizing nonspecific toxicity and enhancing the efficacy of therapy. These drug delivery systems are constructed from materials that are sensitive to a wide range of external stimuli, including light, ultrasound, electrical and magnetic fields, and specific molecules. The responsiveness conferred by these materials allows the release of therapeutics to be triggered on demand and remotely by a physician or patient. In this Review, we describe the rationales for such systems and the types of stimuli that can be deployed, and provide an outlook for the field.

  15. Trigger processing using reconfigurable logic in the CMS calorimeter trigger

    CERN Document Server

    Brooke, J J; Heath, G P; Maddox, A J; Newbold, D; Rabbetts, P D

    2001-01-01

    We present the design of the Global Calorimeter Trigger processor for the CMS detector at LHC. This is a fully pipelined processor system which collects data from all the CMS calorimeters and produces summary information used in forming the Level-1 trigger decision for each event. The design in based on the use of state-of-the-art reconfigurable logic devices (FPGAs) and fast data links. We present the results of device testing using a low-latency pipelined sort algorithm, which demonstrate that an FPGA can be used to perform processing previously foreseen to require custom ASICs. Our design approach results in a powerful, flexible and compact processor system. (0 refs).

  16. Review Document: Full Software Trigger

    CERN Document Server

    Albrecht, J; Raven, G

    2014-01-01

    This document presents a trigger system for the upgraded LHCb detector, scheduled to begin operation in 2020. This document serves as input for the internal review towards the "DAQ, online and trigger TDR". The proposed trigger system is implemented entirely in software. In this document we show that track reconstruction of a similar quality to that available in the offline algorithms can be performed on the full inelastic $pp$-collision rate, without prior event selections implemented in custom hardware and without relying upon a partial event reconstruction. A track nding eciency of 98.8 % relative to oine can be achieved for tracks with $p_T >$ 500 MeV/$c$. The CPU time required for this reconstruction is about 40 % of the available budget. Proof-of-principle selections are presented which demonstrate that excellent performance is achievable using an inclusive beauty trigger, in addition to exclusive beauty and charm triggers. Finally, it is shown that exclusive beauty and charm selections that do not intr...

  17. 55th Annual Canadian Society for Molecular Biosciences Conference on Epigenetics and Genomic Stability. Whistler, British Columbia, Canada, 14–18 March 2012.

    Science.gov (United States)

    Nelson, Christopher J; Ausió, Juan

    2012-06-01

    The 55th Annual Canadian Society for Molecular Biosciences Conference on Epigenetics and Genomic Stability in Whistler, Canada, 14-18 March 2012, brought together 31 speakers from different nationalities. The organizing committee, led by Jim Davie (Chair) at the University of Manitoba (Manitoba, Canada), consisted of several established researchers in the fields of chromatin and epigenetics from across Canada. The meeting was centered on the contribution of epigenetics to gene expression, DNA damage and repair, and the role of environmental factors. A few interesting talks on replication added some insightful information on the controversial issue of histone post-translational modifications as genuine epigenetic marks that are inherited through cell division.

  18. Pitch Angle Scattering of Energetic Electrons by Plasmaspheric Hiss Emissions

    Science.gov (United States)

    Tobita, M.; Omura, Y.; Summers, D.

    2017-12-01

    We study scattering of energetic electrons in pitch angles and kinetic energies through their resonance with plasmaspheric hiss emissions consisting of many coherent discrete whistler-mode wave packets with rising and falling frequencies [1,2,3]. Using test particle simulations, we evaluate the efficiency of scattering, which depends on the inhomogeneity ratio S of whistler mode wave-particle interaction [4]. The value of S is determined by the wave amplitude, frequency sweep rate, and the gradient of the background magnetic field. We first modulate those parameters and observe variations of pitch angles and kinetic energies of electrons with a single wave under various S values so as to obtain basic understanding. We then include many waves into the system to simulate plasmaspheric hiss emissions. As the wave packets propagate away from the magnetic equator, the nonlinear trapping potential at the resonance velocity is deformed, making a channel of gyrophase for untrapped electrons to cross the resonance velocity, and causing modulations in their pitch angles and kinetic energies. We find efficient scattering of pitch angles and kinetic energies because of coherent nonlinear wave-particle interaction, resulting in electron precipitations into the polar atmosphere. We compare the results with the bounce averaged pitch angle diffusion coefficient based on quasi-linear theory, and show that the nonlinear wave model with many coherent packets can cause scattering of resonant electrons much faster than the quasi-linear diffusion process. [1] Summers, D., Omura, Y., Nakamura, S., and C. A. Kletzing (2014), Fine structure of plasmaspheric hiss, J. Geophys. Res., 119, 9134-9149. [2] Omura, Y., Y. Miyashita, M. Yoshikawa, D. Summers, M. Hikishima, Y. Ebihara, and Y. Kubota (2015), Formation process of relativistic electron flux through interaction with chorus emissions in the Earth's inner magnetosphere, J. Geophys. Res. Space Physics, 120, 9545-9562. [3] Nakamura, S., Y

  19. Fast processor for dilepton triggers

    International Nuclear Information System (INIS)

    Katsanevas, S.; Kostarakis, P.; Baltrusaitis, R.

    1983-01-01

    We describe a fast trigger processor, developed for and used in Fermilab experiment E-537, for selecting high-mass dimuon events produced by negative pions and anti-protons. The processor finds candidate tracks by matching hit information received from drift chambers and scintillation counters, and determines their momenta. Invariant masses are calculated for all possible pairs of tracks and an event is accepted if any invariant mass is greater than some preselectable minimum mass. The whole process, accomplished within 5 to 10 microseconds, achieves up to a ten-fold reduction in trigger rate

  20. Upgrade trigger: Bandwidth strategy proposal

    CERN Document Server

    Fitzpatrick, Conor; Meloni, Simone; Boettcher, Thomas Julian; Whitehead, Mark Peter; Dziurda, Agnieszka; Vesterinen, Mika Anton

    2017-01-01

    This document describes a selection strategy for the upgrade trigger using charm signals as a benchmark. The Upgrade trigger uses a 'Run 2-like' sequence consisting of a first and second stage, in between which the calibration and alignment is performed. The first stage, HLT1, uses an inclusive strategy to select beauty and charm decays, while the second stage uses offline-quality exclusive selections. A novel genetic algorithm-based bandwidth division is performed at the second stage to distribute the output bandwidth among different physics channels, maximising the efficiency for useful physics events. The performance is then studied as a function of the available output bandwidth.

  1. Rosacea Triggers: Alcohol and Smoking.

    Science.gov (United States)

    Alinia, Hossein; Tuchayi, Sara Moradi; Patel, Nupur U; Patel, Nishit; Awosika, Olabola; Bahrami, Naeim; Cardwell, Leah A; Richardson, Irma; Huang, Karen E; Feldman, Steven R

    2018-04-01

    A variety of triggers are thought to exacerbate rosacea. A validated self-assessment tool and survey was used to study the relationship between rosacea severity and triggers. Subjects were adult patients with a clinical diagnosis of rosacea. Increased severity of disease was significantly associated with consumption of many alcoholic beverages in 1 day and employment at a job requiring extensive sun exposure. The authors' findings may inform physician counseling practices; patients may be provided with practical measures for managing their rosacea, such as limiting alcohol consumption over short periods of time and increasing sun protection, especially in the summer. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. A New Look at Trigger Point Injections

    OpenAIRE

    Wong, Clara S. M.; Wong, Steven H. S.

    2012-01-01

    Trigger point injections are commonly practised pain interventional techniques. However, there is still lack of objective diagnostic criteria for trigger points. The mechanisms of action of trigger point injection remain obscure and its efficacy remains heterogeneous. The advent of ultrasound technology in the noninvasive real-time imaging of soft tissues sheds new light on visualization of trigger points, explaining the effect of trigger point injection by blockade of peripheral nerves, and ...

  3. A new look at trigger point injections.

    Science.gov (United States)

    Wong, Clara S M; Wong, Steven H S

    2012-01-01

    Trigger point injections are commonly practised pain interventional techniques. However, there is still lack of objective diagnostic criteria for trigger points. The mechanisms of action of trigger point injection remain obscure and its efficacy remains heterogeneous. The advent of ultrasound technology in the noninvasive real-time imaging of soft tissues sheds new light on visualization of trigger points, explaining the effect of trigger point injection by blockade of peripheral nerves, and minimizing the complications of blind injection.

  4. Etiology of myofascial trigger points

    NARCIS (Netherlands)

    Bron, C.; Dommerholt, J.D.

    2012-01-01

    Myofascial pain syndrome (MPS) is described as the sensory, motor, and autonomic symptoms caused by myofascial trigger points (TrPs). Knowing the potential causes of TrPs is important to prevent their development and recurrence, but also to inactivate and eliminate existing TrPs. There is general

  5. Simultaneous observations of quasi-periodic ELF/VLF wave emissions and electron precipitation by DEMETER satellite: A case study

    Czech Academy of Sciences Publication Activity Database

    Hayosh, Mykhaylo; Pasmanik, D. L.; Demekhov, A. G.; Santolík, Ondřej; Parrot, M.; Titova, E. E.

    2013-01-01

    Roč. 118, č. 7 (2013), s. 4523-4533 ISSN 2169-9380 R&D Projects: GA ČR(CZ) GAP209/11/2280; GA MŠk LH12231 Institutional support: RVO:68378289 Keywords : quasi-periodic ELF/VLF emission s in the magnetosphere * wave-particle interactions * demeter spacecraft measurements * whistler-mode waves Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/jgra.50179/abstract

  6. Bandwidths and amplitudes of chorus-like banded emissions measured by the TC-1 Double Star spacecraft

    Czech Academy of Sciences Publication Activity Database

    Macúšová, Eva; Santolík, Ondřej; Cornilleau-Wehrlin, N.; Yearby, K. H.

    2015-01-01

    Roč. 120, č. 2 (2015), s. 1057-1071 ISSN 2169-9380 R&D Projects: GA MŠk(CZ) LH11122; GA ČR GAP205/10/2279; GA ČR(CZ) GAP209/11/2280 EU Projects: European Commission(XE) 284520 - MAARBLE Program:FP7 Institutional support: RVO:68378289 Keywords : Earth's magnetosphere * geomagnetic activity * whistler-mode * chorus emissions Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.318, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/2014JA020440/abstract

  7. Trigger electronics for the ALICE PHOS detector

    CERN Document Server

    Müller, H; Musa, L; Yin, Z; Röhrich, D; Skaali, B; Sibiryak, Yu; Budnikov, D L

    2004-01-01

    The Photon Spectrometer of ALICE consists of 5 identical modules of 56 multiplied by 64 PWO crystals with a total of 100 degree azimuthal coverage of the barrel. The electronics required for implementing both the L0 trigger for high luminosity p-p physics and the L1 trigger for high p//T Pb+Pb physics has been studied. A full integration of the trigger logic into the detector's enclosure is based on analog transmission of fast trigger sums between stacks of front-end boards and trigger-router units. The latter contain 112 digitizer channels of 10bit, which are mapped into a single FPGA per trigger unit, covering areas of 24 multiplied by 16 crystals. The running modes allow for Level-0 trigger at 800ns and Level-1 at 6200ns trigger latencies. The design and status of the PHOS trigger electronics are outlined.

  8. Triggers and Their Influence on Health Behaviors.

    Science.gov (United States)

    Gipson, Christine S

    2017-05-01

    This article provides a conceptual definition of the concept trigger within the context of health behaviors and applies it to the highly significant health issue of obesity. Healthy behaviors are essential to life and happiness, but they do not just happen. They are triggered, and an inner drive keeps them alive. To help patients gain and retain optimal health, nurses must understand the triggers of healthy behaviors. Walker and Avant's (2011) method of concept analysis is used as the basis for defining the concept of trigger. The antecedents, defining attributes, and consequences of trigger are identified. Findings suggest that nurses can play a role in triggering health behavior change through simple motivational efforts.

  9. Muon Trigger for Mobile Phones

    Science.gov (United States)

    Borisyak, M.; Usvyatsov, M.; Mulhearn, M.; Shimmin, C.; Ustyuzhanin, A.

    2017-10-01

    The CRAYFIS experiment proposes to use privately owned mobile phones as a ground detector array for Ultra High Energy Cosmic Rays. Upon interacting with Earth’s atmosphere, these events produce extensive particle showers which can be detected by cameras on mobile phones. A typical shower contains minimally-ionizing particles such as muons. As these particles interact with CMOS image sensors, they may leave tracks of faintly-activated pixels that are sometimes hard to distinguish from random detector noise. Triggers that rely on the presence of very bright pixels within an image frame are not efficient in this case. We present a trigger algorithm based on Convolutional Neural Networks which selects images containing such tracks and are evaluated in a lazy manner: the response of each successive layer is computed only if activation of the current layer satisfies a continuation criterion. Usage of neural networks increases the sensitivity considerably comparable with image thresholding, while the lazy evaluation allows for execution of the trigger under the limited computational power of mobile phones.

  10. ATLAS Level-1 Topological Trigger

    CERN Document Server

    Zheng, Daniel; The ATLAS collaboration

    2018-01-01

    The ATLAS experiment has introduced and recently commissioned a completely new hardware sub-system of its first-level trigger: the topological processor (L1Topo). L1Topo consist of two AdvancedTCA blades mounting state-of-the-art FPGA processors, providing high input bandwidth (up to 4 Gb/s) and low latency data processing (200 ns). L1Topo is able to select collision events by applying kinematic and topological requirements on candidate objects (energy clusters, jets, and muons) measured by calorimeters and muon sub-detectors. Results from data recorded using the L1Topo trigger will be presented. These results demonstrate a significantly improved background event rejection, thus allowing for a rate reduction without efficiency loss. This improvement has been shown for several physics processes leading to low-pT leptons, including H->tau tau and J/Psi->mu mu. In addition to describing the L1Topo trigger system, we will discuss the use of an accurate L1Topo simulation as a powerful tool to validate and optimize...

  11. Industrial accidents triggered by lightning.

    Science.gov (United States)

    Renni, Elisabetta; Krausmann, Elisabeth; Cozzani, Valerio

    2010-12-15

    Natural disasters can cause major accidents in chemical facilities where they can lead to the release of hazardous materials which in turn can result in fires, explosions or toxic dispersion. Lightning strikes are the most frequent cause of major accidents triggered by natural events. In order to contribute towards the development of a quantitative approach for assessing lightning risk at industrial facilities, lightning-triggered accident case histories were retrieved from the major industrial accident databases and analysed to extract information on types of vulnerable equipment, failure dynamics and damage states, as well as on the final consequences of the event. The most vulnerable category of equipment is storage tanks. Lightning damage is incurred by immediate ignition, electrical and electronic systems failure or structural damage with subsequent release. Toxic releases and tank fires tend to be the most common scenarios associated with lightning strikes. Oil, diesel and gasoline are the substances most frequently released during lightning-triggered Natech accidents. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Stimulus conflict triggers behavioral avoidance.

    Science.gov (United States)

    Dignath, David; Eder, Andreas B

    2015-12-01

    According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance.

  13. ATLAS FTK: Fast Track Trigger

    CERN Document Server

    Volpi, Guido; The ATLAS collaboration

    2015-01-01

    An overview of the ATLAS Fast Tracker processor is presented, reporting the design of the system, its expected performance, and the integration status. The next LHC runs, with a significant increase in instantaneous luminosity, will provide a big challenge to the trigger and data acquisition systems of all the experiments. An intensive use of the tracking information at the trigger level will be important to keep high efficiency in interesting events, despite the increase in multiple p-p collisions per bunch crossing (pile-up). In order to increase the use of tracks within the High Level Trigger (HLT), the ATLAS experiment planned the installation of an hardware processor dedicated to tracking: the Fast TracKer (FTK) processor. The FTK is designed to perform full scan track reconstruction at every Level-1 accept. To achieve this goal, the FTK uses a fully parallel architecture, with algorithms designed to exploit the computing power of custom VLSI chips, the Associative Memory, as well as modern FPGAs. The FT...

  14. Ischemic Compression After Trigger Point Injection Affect the Treatment of Myofascial Trigger Points

    OpenAIRE

    Kim, Soo A; Oh, Ki Young; Choi, Won Hyuck; Kim, In Kyum

    2013-01-01

    Objective To investigate the effects of trigger point injection with or without ischemic compression in treatment of myofascial trigger points in the upper trapezius muscle. Methods Sixty patients with active myofascial trigger points in upper trapezius muscle were randomly divided into three groups: group 1 (n=20) received only trigger point injections, group 2 (n=20) received trigger point injections with 30 seconds of ischemic compression, and group 3 (n=20) received trigger point injectio...

  15. Performance of the CMS Regional Calorimeter Trigger

    CERN Document Server

    Klabbers, P; Dasu, S; Efron, J; Fobes, R; Gorski, T; Grogg, K; Grothe, M; Lazaridis, C; Leonard, J; Savin, A; Smith, W H; Weinberg, M

    2009-01-01

    The CMS Regional Calorimeter Trigger (RCT) receives eight-bit energies and a data quality bit from the HCAL and ECAL Trigger Primitive Generators (TPGs). The RCT uses these trigger primitives to find e/γ candidates and calculate regional calorimeter sums that are sent to the Global Calorimeter Trigger (GCT) for sorting and further processing. The RCT hardware consists of one clock distribution crate and 18 double-sided crates containing custom boards, ASICs, and backplanes. The RCT electronics have been completely installed since 2007. The RCT has been integrated into the CMS Level-1 Trigger chain. Regular runs, triggering on cosmic rays, prepare the CMS detector for the restart of the LHC. During this running, the RCT control is handled centrally by CMS Run Control and Monitor System communicating with the Trigger Supervisor. Online Data Quality Monitoring (DQM) evaluates the performance of the RCT during these runs. Offline DQM allows more detailed studies, including trigger efficiencies. These and other r...

  16. Photonuclear reactions triggered by lightning discharge

    Science.gov (United States)

    Enoto, Teruaki; Wada, Yuuki; Furuta, Yoshihiro; Nakazawa, Kazuhiro; Yuasa, Takayuki; Okuda, Kazufumi; Makishima, Kazuo; Sato, Mitsuteru; Sato, Yousuke; Nakano, Toshio; Umemoto, Daigo; Tsuchiya, Harufumi

    2017-11-01

    Lightning and thunderclouds are natural particle accelerators. Avalanches of relativistic runaway electrons, which develop in electric fields within thunderclouds, emit bremsstrahlung γ-rays. These γ-rays have been detected by ground-based observatories, by airborne detectors and as terrestrial γ-ray flashes from space. The energy of the γ-rays is sufficiently high that they can trigger atmospheric photonuclear reactions that produce neutrons and eventually positrons via β+ decay of the unstable radioactive isotopes, most notably 13N, which is generated via 14N + γ → 13N + n, where γ denotes a photon and n a neutron. However, this reaction has hitherto not been observed conclusively, despite increasing observational evidence of neutrons and positrons that are presumably derived from such reactions. Here we report ground-based observations of neutron and positron signals after lightning. During a thunderstorm on 6 February 2017 in Japan, a γ-ray flash with a duration of less than one millisecond was detected at our monitoring sites 0.5-1.7 kilometres away from the lightning. The subsequent γ-ray afterglow subsided quickly, with an exponential decay constant of 40-60 milliseconds, and was followed by prolonged line emission at about 0.511 megaelectronvolts, which lasted for a minute. The observed decay timescale and spectral cutoff at about 10 megaelectronvolts of the γ-ray afterglow are well explained by de-excitation γ-rays from nuclei excited by neutron capture. The centre energy of the prolonged line emission corresponds to electron-positron annihilation, providing conclusive evidence of positrons being produced after the lightning.

  17. A Hardware Track Trigger (FTK) for the ATLAS Trigger

    CERN Document Server

    Zhang, J; The ATLAS collaboration

    2014-01-01

    The design and studies of the performance for the ATLAS hardware Fast TracKer (FTK) are presented. The existing trigger system of the ATLAS experiment is deployed to reduce the event rate from the bunch crossing rate of 40 MHz to < 1 KHz for permanent storage at the LHC design luminosity of 10^34 cm^-2 s^-1. The LHC has performed exceptionally well and routinely exceeds the design luminosity and from 2015 is due to operate with higher still luminosities. This will place a significant load on the High Level trigger (HLT) system, both due to the need for more sophisticated algorithms to reject background, and from the larger data volumes that will need to be processed. The Fast TracKer is a custom electronics system that will operate at the full Level-1 accepted rate of 100 KHz and provide high quality tracks at the beginning of processing in the HLT. This will be performing by track reconstruction using hardware with massive parallelism using associative memories (AM) and FPGAs. The availability of the full...

  18. The D OE software trigger

    International Nuclear Information System (INIS)

    Linnemann, J.T.; Michigan State Univ., East Lansing, MI

    1992-10-01

    In the D OE experiment, the software filter operates in a processor farm with each node processing a single event. Processing is data-driven: the filter does local processing to verify the candidates from the hardware trigger. The filter code consists of independent pieces called ''tools''; processing for a given hardware bit is a ''script'' invoking one or more ''tools'' sequentially. An offline simulator drives the same code with the same configuration files, running on real or simulated data. Online tests use farm nodes parasiting on the data stream. We discuss the performance of the system and how we attempt to verify its correctness

  19. The ALICE high level trigger

    Energy Technology Data Exchange (ETDEWEB)

    Alt, T [Kirchhoff Institute for Physics, University of Heidelberg (Germany); Grastveit, G [Department of Physics and Technology, University of Bergen (Norway); Helstrup, H [Faculty of Engineering, Bergen University College (Norway); Lindenstruth, V [Kirchhoff Institute for Physics, University of Heidelberg (Germany); Loizides, C [Institute for Nuclear Physics, University of Frankfurt (Germany); Roehrich, D [Department of Physics and Technology, University of Bergen (Norway); Skaali, B [Department of Physics, University of Oslo (Norway); Steinbeck, T [Kirchhoff Institute for Physics, University of Heidelberg (Germany); Stock, R [Institute for Nuclear Physics, University of Frankfurt (Germany); Tilsner, H [Kirchhoff Institute for Physics, University of Heidelberg (Germany); Ullaland, K [Department of Physics and Technology, University of Bergen (Norway); Vestboe, A [Faculty of Engineering, Bergen University College (Norway); Vik, T [Department of Physics, University of Oslo (Norway); Wiebalck, A [Kirchhoff Institute for Physics, University of Heidelberg (Germany)

    2004-08-01

    The ALICE experiment at LHC will implement a high-level trigger system for online event selection and/or data compression. The largest computing challenge is posed by the TPC detector, which requires real-time pattern recognition. The system entails a very large processing farm that is designed for an anticipated input data stream of 25 GB s{sup -1}. In this paper, we present the architecture of the system and the current state of the tracking methods and data compression applications.

  20. Triggering for charm, beauty, and truth

    International Nuclear Information System (INIS)

    Appel, J.A.

    1982-02-01

    As the search for more and more rare processes accelerates, the need for more and more effective event triggers also accelerates. In the earliest experiments, a simple coincidence often sufficed not only as the event trigger, but as the complete record of an event of interest. In today's experiments, not only has the fast trigger become more sophisticated, but one or more additional level of trigger processing precedes writing event data to magnetic tape for later analysis. Further search experiments will certainly require further expansion in the number of trigger levels required to filter those rare events of particular interest

  1. Configuration of the ATLAS Trigger System

    CERN Document Server

    Elsing, M; Armstrong, S; Baines, J T M; Bee, C P; Biglietti, M; Bogaerts, A; Boisvert, V; Bosman, M; Brandt, S; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Cervetto, M; Comune, G; Corso-Radu, A; Di Mattia, A; Díaz-Gómez, M; Dos Anjos, A; Drohan, J; Ellis, Nick; Epp, B; Etienne, F; Falciano, S; Farilla, A; George, S; Ghete, V M; González, S; Grothe, M; Kaczmarska, A; Karr, K M; Khomich, A; Konstantinidis, N P; Krasny, W; Li, W; Lowe, A; Luminari, L; Ma, H; Meessen, C; Mello, A G; Merino, G; Morettini, P; Moyse, E; Nairz, A; Negri, A; Nikitin, N V; Nisati, A; Padilla, C; Parodi, F; Pérez-Réale, V; Pinfold, J L; Pinto, P; Polesello, G; Qian, Z; Rajagopalan, S; Resconi, S; Rosati, S; Scannicchio, D A; Schiavi, C; Segura, E; De Seixas, J M; Shears, T G; Sivoklokov, S Yu; Smizanska, M; Soluk, R A; Stanescu, C; Tapprogge, Stefan; Touchard, F; Vercesi, V; Watson, A; Wengler, T; Werner, P; Wheeler, S; Wickens, F J; Wiedenmann, W; Wielers, M; Zobernig, G; CHEP 2003 Computing in High Energy Physics

    2003-01-01

    In this paper a conceptual overview is given of the software foreseen to configure the ATLAS trigger system. Two functional software prototypes have been developed to configure the ATLAS Level-1 emulation and the High-Level Trigger software. Emphasis has been put so far on following a consistent approach between the two trigger systems and on addressing their requirements, taking into account the specific use-case of the `Region-of-Interest' mechanism for the ATLAS Level-2 trigger. In the future the configuration of the two systems will be combined to ensure a consistent selection configuration for the entire ATLAS trigger system.

  2. Whistler intensities above thunderstorms

    Czech Academy of Sciences Publication Activity Database

    Fišer, Jiří; Chum, Jaroslav; Diendorfer, G.; Parrot, M.; Santolík, Ondřej

    2010-01-01

    Roč. 28, č. 1 (2010), s. 37-46 ISSN 0992-7689 R&D Projects: GA ČR GA205/09/1253 Institutional research plan: CEZ:AV0Z30420517 Keywords : Ionosphere (Wave propagation ) * Meteorology and atmospheric dynamics (Lightning) * Radio science ( Waves in plasma) Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.620, year: 2010 http://www.ann-geophys.net/28/37/2010/angeo-28-37-2010.pdf

  3. The Database Driven ATLAS Trigger Configuration System

    CERN Document Server

    Martyniuk, Alex; The ATLAS collaboration

    2015-01-01

    This contribution describes the trigger selection configuration system of the ATLAS low- and high-level trigger (HLT) and the upgrades it received in preparation for LHC Run 2. The ATLAS trigger configuration system is responsible for applying the physics selection parameters for the online data taking at both trigger levels and the proper connection of the trigger lines across those levels. Here the low-level trigger consists of the already existing central trigger (CT) and the new Level-1 Topological trigger (L1Topo), which has been added for Run 2. In detail the tasks of the configuration system during the online data taking are Application of the selection criteria, e.g. energy cuts, minimum multiplicities, trigger object correlation, at the three trigger components L1Topo, CT, and HLT On-the-fly, e.g. rate-dependent, generation and application of prescale factors to the CT and HLT to adjust the trigger rates to the data taking conditions, such as falling luminosity or rate spikes in the detector readout ...

  4. Minimum Bias Interaction Triggers in ATLAS

    CERN Document Server

    Kwee, R E; The ATLAS collaboration

    2010-01-01

    Since the restart of the LHC in November 2009, ATLAS has collected inelastic ppcollisions to perform first measurements on charged particle densities. These measurements will help to constrain various models describing phenomenologically soft parton interactions. Understanding the trigger efficiencies for different event types are therefore crucial to minimize any possible bias in the event selection. ATLAS uses two main minimum bias triggers, featuring complementary detector components and trigger levels. While a hardware based first trigger level situated in the forward regions with 2.2 < |eta| < 3.8 has been proven to select pp-collisions very efficiently, the Inner Detector based minimum bias trigger uses a random seed on filled bunches and central tracking detectors for the event selection. Both triggers were essential for the analysis of kinematic spectra of charged particles. Their performance and trigger efficiency measurements as well as studies on possible bias sources will be presente...

  5. Hadronic triggers and trigger object-level analysis at ATLAS

    CERN Document Server

    Zaripovas, Donatas Ramilas; The ATLAS collaboration

    2017-01-01

    Hadronic signatures are critical to the high energy physics analysis program at the Large Hadron Collider (LHC), and are broadly used for both Standard Model measurements and searches for new physics. These signatures include generic quark and gluon jets, as well as jets originating from b-quarks or the decay of massive particles (such as electroweak bosons or top quarks). Additionally missing transverse momentum from non-interacting particles provides an interesting probe in the search for new physics beyond the Standard Model. Developing trigger selections that target these events is a huge challenge at the LHC due to the enormous event rates associated with these signatures. This challenge is exacerbated by the amount of pile-up activity, which continues to grow. In order to address these challenges, several new techniques have been developed during the past year in order to significantly improve the potential of the 2017 dataset and overcome the limiting factors, such as storage and computing requirements...

  6. Hadronic Triggers and trigger-object level analysis at ATLAS

    CERN Document Server

    Zaripovas, Donatas Ramilas; The ATLAS collaboration

    2017-01-01

    Hadronic signatures are critical to the high energy physics analysis program, and are broadly used for both Standard Model measurements and searches for new physics. These signatures include generic quark and gluon jets, as well as jets originating from b-quarks or the decay of massive particles (such as electroweak bosons or top quarks). Additionally missing transverse momentum from non-interacting particles provides an interesting probe in the search for new physics beyond the Standard Model. Developing trigger selections that target these events is a huge challenge at the LHC due to the enormous rates associated with these signatures. This challenge is exacerbated by the amount of pile-up activity, which continues to grow. In order to address these challenges, several new techniques have been developed during the past year in order to significantly improve the potential of the 2017 dataset and overcome the limiting factors to more deeply probing for new physics, such as storage and computing requirements f...

  7. Dependence of Generation of Whistler Mode Chorus Emissions on the Temperature Anisotropy and Density of Energetic Electrons in the Earth's Inner Magnetosphere

    Science.gov (United States)

    Katoh, Y.; Omura, Y.; Miyake, Y.; Usui, H.; Nakashima, H.

    2018-02-01

    We carry out a series of self-consistent electron hybrid code simulations for the dependence of chorus generation process on the temperature anisotropy and density of energetic electrons in the Earth's inner magnetosphere. We use the same magnetic field gradient in the simulation system and different temperature anisotropy AT for the initial distribution of energetic electrons at the magnetic equator. We conduct 6 sets of simulations for different AT from 4 to 9, changing the initial number density Nh of energetic electrons at the equator in each set of simulations. By analyzing the spectra obtained in the simulation results, we identify chorus elements with rising tones in the results for higher Nh but no distinct chorus in smaller Nh. We compare the simulation results with estimations of the threshold and optimum amplitude proposed by the nonlinear wave growth theory. We find that the chorus generation processes reproduced in the simulation results are consistently explained by the theoretical estimates. We also compare the simulation results with linear growth rates for all simulation runs. We find clear disagreement between the spectral characteristics of reproduced chorus and the predictions by the linear theory. The present study clarifies that the spectra of chorus are essentially different from those predicted by the linear theory and are determined fully by nonlinear processes of wave-particle interactions in the chorus generation region.

  8. Wired and Wireless Camera Triggering with Arduino

    Science.gov (United States)

    Kauhanen, H.; Rönnholm, P.

    2017-10-01

    Synchronous triggering is an important task that allows simultaneous data capture from multiple cameras. Accurate synchronization enables 3D measurements of moving objects or from a moving platform. In this paper, we describe one wired and four wireless variations of Arduino-based low-cost remote trigger systems designed to provide a synchronous trigger signal for industrial cameras. Our wireless systems utilize 315 MHz or 434 MHz frequencies with noise filtering capacitors. In order to validate the synchronization accuracy, we developed a prototype of a rotating trigger detection system (named RoTriDeS). This system is suitable to detect the triggering accuracy of global shutter cameras. As a result, the wired system indicated an 8.91 μs mean triggering time difference between two cameras. Corresponding mean values for the four wireless triggering systems varied between 7.92 and 9.42 μs. Presented values include both camera-based and trigger-based desynchronization. Arduino-based triggering systems appeared to be feasible, and they have the potential to be extended to more complicated triggering systems.

  9. Acoustic localization of triggered lightning

    Science.gov (United States)

    Arechiga, Rene O.; Johnson, Jeffrey B.; Edens, Harald E.; Thomas, Ronald J.; Rison, William

    2011-05-01

    We use acoustic (3.3-500 Hz) arrays to locate local (thunder produced by triggered lightning in the Magdalena Mountains of central New Mexico. The locations of the thunder sources are determined by the array back azimuth and the elapsed time since discharge of the lightning flash. We compare the acoustic source locations with those obtained by the Lightning Mapping Array (LMA) from Langmuir Laboratory, which is capable of accurately locating the lightning channels. To estimate the location accuracy of the acoustic array we performed Monte Carlo simulations and measured the distance (nearest neighbors) between acoustic and LMA sources. For close sources (6 km) the error increases to 800 m for the nearest neighbors and 650 m for the Monte Carlo analysis. This work shows that thunder sources can be accurately located using acoustic signals.

  10. Does Aluminium Trigger Breast Cancer?

    Directory of Open Access Journals (Sweden)

    Peter Jennrich

    2016-08-01

    Full Text Available Summary. Breast cancer is by far the most common cancer in women in the western world. In 90% of breast cancers, environmental factors are among the causes. The frequency with which the tumour occurs in the outer upper part of the breast has risen with above average rates in recent decades. Aluminium salts as ingredients in deodorants and antiperspirants are being absorbed by the body to a greater extent than hitherto assumed. Their toxicity for healthy and diseased breast tissue cells includes various well-documented pathomechanisms. In the sense of primary and secondary prevention, the cancer-triggering potential of aluminium and its use in anti-perspirant deodorants must be re-evaluated. For the same reason the access to a targeted diagnosis and treatment of aluminium loading must be facilitated.

  11. Landslide triggering by rain infiltration

    Science.gov (United States)

    Iverson, Richard M.

    2000-01-01

    Landsliding in response to rainfall involves physical processes that operate on disparate timescales. Relationships between these timescales guide development of a mathematical model that uses reduced forms of Richards equation to evaluate effects of rainfall infiltration on landslide occurrence, timing, depth, and acceleration in diverse situations. The longest pertinent timescale is A/D0, where D0 is the maximum hydraulic diffusivity of the soil and A is the catchment area that potentially affects groundwater pressures at a prospective landslide slip surface location with areal coordinates x, y and depth H. Times greater than A/D0 are necessary for establishment of steady background water pressures that develop at (x, y, H) in response to rainfall averaged over periods that commonly range from days to many decades. These steady groundwater pressures influence the propensity for landsliding at (x, y, H), but they do not trigger slope failure. Failure results from rainfall over a typically shorter timescale H2/D0 associated with transient pore pressure transmission during and following storms. Commonly, this timescale ranges from minutes to months. The shortest timescale affecting landslide responses to rainfall is √(H/g), where g is the magnitude of gravitational acceleration. Postfailure landslide motion occurs on this timescale, which indicates that the thinnest landslides accelerate most quickly if all other factors are constant. Effects of hydrologic processes on landslide processes across these diverse timescales are encapsulated by a response function, R(t*) = √(t*/π) exp (-1/t*) - erfc (1/√t*), which depends only on normalized time, t*. Use of R(t*) in conjunction with topographic data, rainfall intensity and duration information, an infinite-slope failure criterion, and Newton's second law predicts the timing, depth, and acceleration of rainfall-triggered landslides. Data from contrasting landslides that exhibit rapid, shallow motion and slow, deep

  12. Triggers of oral lichen planus flares and the potential role of trigger avoidance in disease management.

    Science.gov (United States)

    Chen, Hannah X; Blasiak, Rachel; Kim, Edwin; Padilla, Ricardo; Culton, Donna A

    2017-09-01

    Many patients with oral lichen planus (OLP) report triggers of flares, some of which overlap with triggers of other oral diseases, including oral allergy syndrome and oral contact dermatitis. The purpose of this study was to evaluate the prevalence of commonly reported triggers of OLP flares, their overlap with triggers of other oral diseases, and the potential role of trigger avoidance as a management strategy. Questionnaire-based survey of 51 patients with biopsy-proven lichen planus with oral involvement seen in an academic dermatology specialty clinic and/or oral pathology clinic between June 2014 and June 2015. Of the participants, 94% identified at least one trigger of their OLP flares. Approximately half of the participants (51%) reported at least one trigger that overlapped with known triggers of oral allergy syndrome, and 63% identified at least one trigger that overlapped with known triggers of oral contact dermatitis. Emotional stress was the most commonly reported trigger (77%). Regarding avoidance, 79% of the study participants reported avoiding their known triggers in daily life. Of those who actively avoided triggers, 89% reported an improvement in symptoms and 70% reported a decrease in the frequency of flares. Trigger identification and avoidance can play a potentially effective role in the management of OLP. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Smart trigger logic for focal plane arrays

    Science.gov (United States)

    Levy, James E; Campbell, David V; Holmes, Michael L; Lovejoy, Robert; Wojciechowski, Kenneth; Kay, Randolph R; Cavanaugh, William S; Gurrieri, Thomas M

    2014-03-25

    An electronic device includes a memory configured to receive data representing light intensity values from pixels in a focal plane array and a processor that analyzes the received data to determine which light values correspond to triggered pixels, where the triggered pixels are those pixels that meet a predefined set of criteria, and determines, for each triggered pixel, a set of neighbor pixels for which light intensity values are to be stored. The electronic device also includes a buffer that temporarily stores light intensity values for at least one previously processed row of pixels, so that when a triggered pixel is identified in a current row, light intensity values for the neighbor pixels in the previously processed row and for the triggered pixel are persistently stored, as well as a data transmitter that transmits the persistently stored light intensity values for the triggered and neighbor pixels to a data receiver.

  14. The ATLAS b-jet Trigger

    CERN Document Server

    Ferreira de Lima, D E; The ATLAS collaboration

    2011-01-01

    The ATLAS b-jet Trigger The online event selection is crucial to reject most of the events containing uninteresting background collisions while preserving as much as possible the interesting physical signals. The b-jet selection is part of the trigger strategy of the ATLAS experiment and a set of dedicated triggers is presently contributing to the event selection for the 2011 running. The b-jets acceptance is increased and the background reduced by lowering jet transverse energy thresholds at the first trigger level and applying b-tagging techniques at the subsequent levels. Different physics channels, especially topologies containing more than one b-jet where higher rejection factors are achieved, benefit from requesting this trigger to be fired. An overview of the status-of-art of the b-jet trigger menu and performance on real data is presented in this poster.

  15. Propagation of lower-band whistler-mode waves in the outer Van Allen belt: Systematic analysis of 11 years of multi-component data from the Cluster spacecraft

    Czech Academy of Sciences Publication Activity Database

    Santolík, Ondřej; Macúšová, Eva; Kolmašová, Ivana; Cornilleau-Wehrlin, N.; De Conchy, Y.

    2014-01-01

    Roč. 41, č. 8 (2014), s. 2729-2737 ISSN 0094-8276 R&D Projects: GA MŠk 7E12026; GA ČR GAP205/10/2279 Institutional support: RVO:68378289 Keywords : whistler-mode chorus * wave vector directions * Van Allen radiation belts Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.456, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/2014GL059815/abstract

  16. Upgrade trigger & reconstruction strategy: 2017 milestone

    CERN Document Server

    Albrecht, Johannes; Campora Perez, Daniel Hugo; Cattaneo, Marco; Marco, Clemencic; Couturier, Ben; Dziurda, Agnieszka; Fitzpatrick, Conor; Grillo, Lucia; Hasse, Christoph; Jones, Christopher Rob; Lemaitre, Florian; Lupton, Olli; Matev, Rosen; Pearce, Alex; Promberger, Laura; Ponce, Sebastien; Quagliani, Renato; Raven, Gerhard; Schiller, Manuel Tobias; Sciascia, Barbara; Szymanski, Maciej Pawel; Stahl, Sascha

    2018-01-01

    The LHCb collaboration is currently preparing an update of the experiment to take data in Run 3 of the LHC. The dominant feature of this upgrade is a trigger-less readout of the full detector followed by a full software trigger. To make optimal use of the collected data, the events are reconstructed at the inelastic collision rate of 30 MHz. This document presents the baseline trigger and reconstruction strategy as of the end of 2017.

  17. Configuration of the ATLAS Trigger System

    OpenAIRE

    Elsing, M; Schörner-Sadenius, T; Armstrong, S; Baines, J T M; Bee, C P; Biglietti, M; Bogaerts, A; Boisvert, V; Bosman, M; Brandt, S; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Cervetto, M

    2003-01-01

    In this paper a conceptual overview is given of the software foreseen to configure the ATLAS trigger system. Two functional software prototypes have been developed to configure the ATLAS Level-1 emulation and the High-Level Trigger software. Emphasis has been put so far on following a consistent approach between the two trigger systems and on addressing their requirements, taking into account the specific use-case of the `Region-of-Interest' mechanism for the ATLAS Level-2 trigger. In the fut...

  18. The ATLAS Muon and Tau Trigger

    CERN Document Server

    Dell'Asta, L; The ATLAS collaboration

    2013-01-01

    [Muon] The ATLAS experiment at CERN's Large Hadron Collider (LHC) deploys a three-levels processing scheme for the trigger system. The level-1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The muon HLT is purely software based and encompasses a level-2 (L2) trigger followed by an event filter (EF) for a staged trigger approach. It has access to the data of the precision muon detectors and other detector elements to refine the muon hypothesis. Trigger-specific algorithms were developed and are used for the L2 to increase processing speed for instance by making use of look-up tables and simpler algorithms, while the EF muon triggers mostly benefit from offline reconstruction software to obtain most precise determination of the track parameters. There are two algorithms with different approaches, namely inside-out and outside-in...

  19. A Novel in situ Trigger Combination Method

    International Nuclear Information System (INIS)

    Buzatu, Adrian; Warburton, Andreas; Krumnack, Nils; Yao, Wei-Ming

    2012-01-01

    Searches for rare physics processes using particle detectors in high-luminosity colliding hadronic beam environments require the use of multi-level trigger systems to reject colossal background rates in real time. In analyses like the search for the Higgs boson, there is a need to maximize the signal acceptance by combining multiple different trigger chains when forming the offline data sample. In such statistically limited searches, datasets are often amassed over periods of several years, during which the trigger characteristics evolve and their performance can vary significantly. Reliable production cross-section measurements and upper limits must take into account a detailed understanding of the effective trigger inefficiency for every selected candidate event. We present as an example the complex situation of three trigger chains, based on missing energy and jet energy, to be combined in the context of the search for the Higgs (H) boson produced in association with a W boson at the Collider Detector at Fermilab (CDF). We briefly review the existing techniques for combining triggers, namely the inclusion, division, and exclusion methods. We introduce and describe a novel fourth in situ method whereby, for each candidate event, only the trigger chain with the highest a priori probability of selecting the event is considered. The in situ combination method has advantages of scalability to large numbers of differing trigger chains and of insensitivity to correlations between triggers. We compare the inclusion and in situ methods for signal event yields in the CDF WH search.

  20. Data analysis at Level-1 Trigger level

    CERN Document Server

    Wittmann, Johannes; Aradi, Gregor; Bergauer, Herbert; Jeitler, Manfred; Wulz, Claudia; Apanasevich, Leonard; Winer, Brian; Puigh, Darren Michael

    2017-01-01

    With ever increasing luminosity at the LHC, optimum online data selection is getting more and more important. While in the case of some experiments (LHCb and ALICE) this task is being completely transferred to computer farms, the others - ATLAS and CMS - will not be able to do this in the medium-term future for technological, detector-related reasons. Therefore, these experiments pursue the complementary approach of migrating more and more of the offline and High-Level Trigger intelligence into the trigger electronics. This paper illustrates how the Level-1 Trigger of the CMS experiment and in particular its concluding stage, the Global Trigger, take up this challenge.

  1. Landslide triggering by rain infiltration

    Science.gov (United States)

    Iverson, Richard M.

    2000-01-01

    Landsliding in response to rainfall involves physical processes that operate on disparate timescales. Relationships between these timescales guide development of a mathematical model that uses reduced forms of Richards equation to evaluate effects of rainfall infiltration on landslide occurrence, timing, depth, and acceleration in diverse situations. The longest pertinent timescale is A/D0, where D0 is the maximum hydraulic diffusivity of the soil and A is the catchment area that potentially affects groundwater pressures at a prospective landslide slip surface location with areal coordinates x, y and depth H. Times greater than A/D0 are necessary for establishment of steady background water pressures that develop at (x, y, H) in response to rainfall averaged over periods that commonly range from days to many decades. These steady groundwater pressures influence the propensity for landsliding at (x, y, H), but they do not trigger slope failure. Failure results from rainfall over a typically shorter timescale H2/D0 associated with transient pore pressure transmission during and following storms. Commonly, this timescale ranges from minutes to months. The shortest timescale affecting landslide responses to rainfall is √(H/g), where g is the magnitude of gravitational acceleration. Postfailure landslide motion occurs on this timescale, which indicates that the thinnest landslides accelerate most quickly if all other factors are constant. Effects of hydrologic processes on landslide processes across these diverse timescales are encapsulated by a response function, R(t*) = √(t*/π) exp (-1/t*) - erfc (1/√t*), which depends only on normalized time, t*. Use of R(t*) in conjunction with topographic data, rainfall intensity and duration information, an infinite-slope failure criterion, and Newton's second law predicts the timing, depth, and acceleration of rainfall-triggered landslides. Data from contrasting landslides that exhibit rapid, shallow

  2. Viral triggers of multiple sclerosis.

    Science.gov (United States)

    Kakalacheva, Kristina; Münz, Christian; Lünemann, Jan D

    2011-02-01

    Genetic and environmental factors jointly determine the susceptibility to develop Multiple Sclerosis (MS). Collaborative efforts during the past years achieved substantial progress in defining the genetic architecture, underlying susceptibility to MS. Similar to other autoimmune diseases, HLA-DR and HLA-DQ alleles within the HLA class II region on chromosome 6p21 are the highest-risk-conferring genes. Less-robust susceptibility effects have been identified for MHC class I alleles and for non-MHC regions. The role of environmental risk factors and their interaction with genetic susceptibility alleles are much less well defined, despite the fact that infections have long been associated with MS development. Current data suggest that infectious triggers are most likely ubiquitous, i.e., highly prevalent in the general population, and that they require a permissive genetic trait which predisposes for MS development. In this review article, we illustrate mechanisms of infection-induced immunopathologies in experimental animal models of autoimmune CNS inflammation, discuss challenges for the translation of these experimental data into human immunology research, and provide future perspectives on how novel model systems could be utilized to better define the role of viral pathogens in MS. 2010 Elsevier B.V. All rights reserved.

  3. The trigger supervisor: Managing triggering conditions in a high energy physics experiment

    International Nuclear Information System (INIS)

    Wadsworth, B.; Lanza, R.; LeVine, M.J.; Scheetz, R.A.; Videbaek, F.

    1987-01-01

    A trigger supervisor, implemented in VME-bus hardware, is described, which enables the host computer to dynamically control and monitor the trigger configuration for acquiring data from multiple detector partitions in a complex experiment

  4. Tools for Trigger Aware Analyses in ATLAS

    CERN Document Server

    Krasznahorkay, A; The ATLAS collaboration; Stelzer, J

    2010-01-01

    In order to search for rare processes, all four LHC experiments have to use advanced triggering methods for selecting and recording the events of interest. At the expected nominal LHC operating conditions only about 0.0005% of the collision events can be kept for physics analysis in ATLAS. Therefore the understanding and evaluation of the trigger performance is one of the most crucial parts of any physics analysis. ATLAS’s first level trigger is composed of custom-built hardware, while the second and third levels are implemented using regular PCs running reconstruction and selection algorithms. Because of this split, accessing the results of the trigger execution for the two stages is different. The complexity of the software trigger presents further difficulties in accessing the trigger data. To make the job of the physicists easier when evaluating the trigger performance, multiple general-use tools are provided by the ATLAS Trigger Analysis Tools group. The TrigDecisionTool, a general tool, is provided to...

  5. Trigger factors for familial hemiplegic migraine

    DEFF Research Database (Denmark)

    Hansen, Jakob Møller; Hauge, Anne Werner; Ashina, Messoud

    2011-01-01

    The aim was to identify and describe migraine trigger factors in patients with familial hemiplegic migraine (FHM) from a population-based sample.......The aim was to identify and describe migraine trigger factors in patients with familial hemiplegic migraine (FHM) from a population-based sample....

  6. Supine Breast MRI Using Respiratory Triggering

    NARCIS (Netherlands)

    Janssen, Natasja N. Y.; ter Beek, Leon C.; Loo, Claudette E.; Winter-Warnars, Gonneke; Lange, Charlotte A. H.; van Loveren, Marjolein; Alderliesten, Tanja; Sonke, Jan-Jakob; Nijkamp, Jasper

    2017-01-01

    This study aims to evaluate if navigator-echo respiratory-triggered magnetic resonance acquisition can acquire supine high-quality breast magnetic resonance imaging (MRI). Supine respiratory-triggered magnetic resonance imaging (Trig-MRI) was compared to supine non-Trig-MRI to evaluate

  7. Report of the trigger processor subgroup

    International Nuclear Information System (INIS)

    Johnson, M.

    1993-01-01

    This is a summary report of a small group of people who met one afternoon to discuss trigger processors. The trigger processor group spent much of its time discussing new architecture's for high rate experiments. There was an attempt to differentiate between data driven architectures and the more conventional systems where triggers are divided into a series of levels. This was not too successful because most people felt that there were elements of the data driven architecture in almost all trigger systems -- particularly at the front end. There are, however, broad divisions that are present in almost every trigger system. The typical trigger levels are defined as: level 1 - This is the section of the trigger that is truly dead timeless. The data is pipelined with enough buffers so that no crossing (event in fixed target) is lost. A trigger decision is generated at every crossing (but delayed by the length of the pipeline); level 3 - Processor farm with one complete event per processor; level 2 - Everything in between

  8. Do episodes of anger trigger myocardial infarction?

    DEFF Research Database (Denmark)

    Möller, J; Hallqvist, J; Diderichsen, Finn

    1999-01-01

    Our objectives were to study anger as a trigger of acute myocardial infarction (MI) and to explore potential effect modification by usual behavioral patterns related to hostility.......Our objectives were to study anger as a trigger of acute myocardial infarction (MI) and to explore potential effect modification by usual behavioral patterns related to hostility....

  9. The LVL2 trigger goes online

    CERN Document Server

    David Berge

    On Friday, the 9th of February, the ATLAS TDAQ community reached an important milestone. In a successful integration test, cosmic-ray muons were recorded with parts of the muon spectrometer, the central-trigger system and a second-level trigger algorithm. This was actually the first time that a full trigger slice all the way from the first-level trigger muon chambers up to event building after event selection by the second-level trigger ran online with cosmic rays. The ATLAS trigger and data acquisition system has a three-tier structure that is designed to cope with the enormous demands of proton-proton collisions at a bunch-crossing frequency of 40 MHz, with a typical event size of 1-2 MB. The online event selection has to reduce the incoming rate by a factor of roughly 200,000 to 200 Hz, a rate digestible by the archival-storage and offline-processing facilities. ATLAS has a mixed system: the first-level trigger (LVL1) is in hardware, while the other two consecutive levels, the second-level trigger (LVL2)...

  10. The ATLAS Level-1 Topological Trigger Performance

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00371751; The ATLAS collaboration

    2016-01-01

    The LHC will collide protons in the ATLAS detector with increasing luminosity through 2016, placing stringent operational and physical requirements to the ATLAS trigger system in order to reduce the 40 MHz collision rate to a manageable event storage rate of 1 kHz, while not rejecting interesting physics events. The Level-1 trigger is the first rate-reducing step in the ATLAS trigger system with an output rate of 100 kHz and decision latency smaller than 2.5 μs. It consists of a calorimeter trigger, muon trigger and a central trigger processor. During the LHC shutdown after the Run 1 finished in 2013, the Level-1 trigger system was upgraded including hardware, firmware and software updates. In particular, new electronics modules were introduced in the real-time data processing path: the Topological Processor System (L1Topo). It consists of a single AdvancedCTA shelf equipped with two Level-1 topological processor blades. They receive real-time information from the Level-1 calorimeter and muon triggers, which...

  11. Intelligent trigger processor for the crystal box

    CERN Document Server

    Sanders, G H; Cooper, M D; Hart, G W; Hoffman, C M; Hogan, G E; Hughes, E B; Matis, H S; Rolfe, J; Sandberg, V D; Williams, R A; Wilson, S; Zeman, H

    1981-01-01

    A large solid angle angular modular NaI(Tl) detector with 432 phototubes and 88 trigger scintillators is being used to search simultaneously for three lepton flavor-changing decays of the muon. A beam of up to 10/sup 6/ muons stopping per second with a 6% duty factor would yield up to 1000 triggers per second from random triple coincidences. A reduction of the trigger rate to 10 Hz is required from a hardwired primary trigger processor. Further reduction to <1 Hz is achieved by a microprocessor-based secondary trigger processor. The primary trigger hardware imposes voter coincidence logic, stringent timing requirements, and a non-adjacency requirement in the trigger scintillators defined by hardwired circuits. Sophisticated geometric requirements are imposed by a PROM-based matrix logic, and energy and vector-momentum cuts are imposed by a hardwired processor using LSI flash ADC's and digital arithmetic logic. The secondary trigger employs four satellite microprocessors to do a sparse data scan, multiplex ...

  12. A general-purpose trigger processor system and its application to fast vertex trigger

    International Nuclear Information System (INIS)

    Hazumi, M.; Banas, E.; Natkaniec, Z.; Ostrowicz, W.

    1997-12-01

    A general-purpose hardware trigger system has been developed. The system comprises programmable trigger processors and pattern generator/samplers. The hardware design of the system is described. An application as a prototype of the very fast vertex trigger in an asymmetric B-factory at KEK is also explained. (author)

  13. Ischemic compression after trigger point injection affect the treatment of myofascial trigger points.

    Science.gov (United States)

    Kim, Soo A; Oh, Ki Young; Choi, Won Hyuck; Kim, In Kyum

    2013-08-01

    To investigate the effects of trigger point injection with or without ischemic compression in treatment of myofascial trigger points in the upper trapezius muscle. SIXTY PATIENTS WITH ACTIVE MYOFASCIAL TRIGGER POINTS IN UPPER TRAPEZIUS MUSCLE WERE RANDOMLY DIVIDED INTO THREE GROUPS: group 1 (n=20) received only trigger point injections, group 2 (n=20) received trigger point injections with 30 seconds of ischemic compression, and group 3 (n=20) received trigger point injections with 60 seconds of ischemic compression. The visual analogue scale, pressure pain threshold, and range of motion of the neck were assessed before treatment, immediately after treatment, and 1 week after treatment. Korean Neck Disability Indexes were assessed before treatment and 1 week after treatment. We found a significant improvement in all assessment parameters (ptrigger point injections with ischemic compression group showed significant improvement as compared with the receiving only trigger point injections group. And no significant differences between receiving 30 seconds of ischemic compression group and 60 seconds of ischemic compression group. This study demonstrated the effectiveness of ischemic compression for myofascial trigger point. Trigger point injections combined with ischemic compression shows better effects on treatment of myofascial trigger points in the upper trapezius muscle than the only trigger point injections therapy. But the duration of ischemic compression did not affect treatment of myofascial trigger point.

  14. Reliability model analysis and primary experimental evaluation of laser triggered pulse trigger

    International Nuclear Information System (INIS)

    Chen Debiao; Yang Xinglin; Li Yuan; Li Jin

    2012-01-01

    High performance pulse trigger can enhance performance and stability of the PPS. It is necessary to evaluate the reliability of the LTGS pulse trigger, so we establish the reliability analysis model of this pulse trigger based on CARMES software, the reliability evaluation is accord with the statistical results. (authors)

  15. MR imaging findings of trigger thumb

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Eric Y.; Chen, Karen C.; Chung, Christine B. [VA San Diego Healthcare System, Radiology Service, San Diego, CA (United States); University of California, San Diego Medical Center, Department of Radiology, San Diego, CA (United States)

    2015-08-15

    Trigger finger (or trigger thumb), also known as sclerosing tenosynovitis, is a common clinical diagnosis that rarely presents for imaging. Because of this selection bias, many radiologists may not be familiar with the process. Furthermore, patients who do present for imaging frequently have misleading examination indications. To our knowledge, magnetic resonance (MR) imaging findings of trigger thumb have not been previously reported in the literature. In this article, we review the entity of trigger thumb, the anatomy involved, and associated imaging findings, which include flexor pollicis longus tendinosis with a distinct nodule, A1 pulley thickening, and tenosynovitis. In addition, in some cases, an abnormal Av pulley is apparent. In the rare cases of trigger finger that present for MR imaging, accurate diagnosis by the radiologist can allow initiation of treatment and avoid further unnecessary workup. (orig.)

  16. MR imaging findings of trigger thumb

    International Nuclear Information System (INIS)

    Chang, Eric Y.; Chen, Karen C.; Chung, Christine B.

    2015-01-01

    Trigger finger (or trigger thumb), also known as sclerosing tenosynovitis, is a common clinical diagnosis that rarely presents for imaging. Because of this selection bias, many radiologists may not be familiar with the process. Furthermore, patients who do present for imaging frequently have misleading examination indications. To our knowledge, magnetic resonance (MR) imaging findings of trigger thumb have not been previously reported in the literature. In this article, we review the entity of trigger thumb, the anatomy involved, and associated imaging findings, which include flexor pollicis longus tendinosis with a distinct nodule, A1 pulley thickening, and tenosynovitis. In addition, in some cases, an abnormal Av pulley is apparent. In the rare cases of trigger finger that present for MR imaging, accurate diagnosis by the radiologist can allow initiation of treatment and avoid further unnecessary workup. (orig.)

  17. The LHCb Trigger System: Present and Future

    Science.gov (United States)

    Albrecht, Johannes; LHCb Collaboration

    2015-06-01

    The current LHCb trigger system consists of a hardware level, which reduces the LHC inelastic collision rate of 30 MHz to 1MHz, at which the entire detector is read out. In a second level, implemented in a CPU farm, the event rate is reduced to about 5 kHz. The major bottleneck in LHCb's trigger efficiencies for hadronic heavy flavour decays is the hardware trigger. The LHCb experiment plans a major upgrade of the detector and DAQ system in the LHC shutdown of 2018. In this upgrade, a purely software based trigger system is being developed, which will have to process the full 30 MHz of inelastic collisions delivered by the LHC. Both the current trigger system and its planned upgrade are discussed in these proceedings.

  18. Concept of the CMS Trigger Supervisor

    CERN Document Server

    Magrans de Abril, Ildefons; Varela, Joao

    2006-01-01

    The Trigger Supervisor is an online software system designed for the CMS experiment at CERN. Its purpose is to provide a framework to set up, test, operate and monitor the trigger components on one hand and to manage their interplay and the information exchange with the run control part of the data acquisition system on the other. The Trigger Supervisor is conceived to provide a simple and homogeneous client interface to the online software infrastructure of the trigger subsystems. This document specifies the functional and non-functional requirements, design and operational details, and the components that will be delivered in order to facilitate a smooth integration of the trigger software in the context of CMS.

  19. Pulse triggering mechanism of air proportional counters

    International Nuclear Information System (INIS)

    Aoyama, T.; Mori, T.; Watanabe, T.

    1983-01-01

    This paper describes the pulse triggering mechanism of a cylindrical proportional counter filled with air at atmospheric pressure for the incidence of β-rays. Experimental results indicate that primary electrons created distantly from the anode wire by a β-ray are transformed into negative ions, which then detach electrons close to the anode wire and generate electron avalanches thus triggering pulses, while electrons created near the anode wire by a β-ray directly trigger a pulse. Since a negative ion pulse is triggered by a single electron detached from a negative ion, multiple pulses are generated by a large number of ions produced by the incidence of a single β-ray. It is therefore necessary not to count pulses triggered by negative ions but to count those by primary electrons alone when use is made of air proportional counters for the detection of β-rays. (orig.)

  20. ATLAS jet trigger performance in 2016 data

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00535667; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the LHC uses a two-level trigger system to preferentially select events with a predefined topology of interest for future analysis. The hadronic jet trigger is used to select several different topologies containing different types and multiplicities of hadronic jets, thus supporting many different physics searches and measurements. The hadronic jet trigger efficiency for proton-proton collision data at a centre-of-mass energy of 13 TeV is presented. The efficient selection of events containing hadronic jets requires the characteristics of trigger-level jets and offline jets to be very similar. A comparison of relevant characteristics demonstrates that trigger-level jets and offline jets are in excellent agreement.

  1. ATLAS jet trigger performance in 2015 data

    CERN Document Server

    Herwig, Theodor Christian; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the LHC uses a two-level trigger system to preferentially select events with a predefined topology of interest for future analysis. The hadronic jet trigger is used to select several different topologies containing different types and multiplicities of hadronic jets, thus supporting many different physics searches and measurements. The hadronic jet trigger efficiency for proton-proton collision data at a centre-of-mass energy of 13 TeV is presented. The efficient selection of events containing hadronic jets requires the characteristics of trigger-level jets and offline jets to be very similar. A comparison of relevant characteristics demonstrates that trigger-level jets and offline jets are in excellent agreement.

  2. Emissions Trading

    NARCIS (Netherlands)

    Woerdman, Edwin; Backhaus, Juergen

    2014-01-01

    Emissions trading is a market-based instrument to achieve environmental targets in a cost-effective way by allowing legal entities to buy and sell emission rights. The current international dissemination and intended linking of emissions trading schemes underlines the growing relevance of this

  3. Dark matter triggers of supernovae

    Science.gov (United States)

    Graham, Peter W.; Rajendran, Surjeet; Varela, Jaime

    2015-09-01

    The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to 1.25 M⊙ rules out primordial black holes with masses ˜1019- 1020 gm as a dominant constituent of the local dark matter density. Black holes with masses as large as 1024 gm will be excluded if recent observations by the NuStar Collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range 1020- 1022 gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism proposed in this paper can constrain a variety of other dark matter scenarios such as Q balls, annihilation/collision of large composite states of dark matter and models of dark matter where the accretion of dark matter leads to the formation of compact cores within the star. White dwarfs, with their astronomical lifetimes and sizes, can thus act as large spacetime volume detectors enabling a unique probe of the properties of dark matter, especially of dark matter candidates that have low number density. This mechanism also raises the intriguing possibility that a class of supernova may be triggered through rare events induced by dark matter rather than the conventional mechanism of accreting white dwarfs that explode upon reaching the Chandrasekhar mass.

  4. Magma degassing triggered by static decompression at Kīlauea Volcano, Hawai‘i

    Science.gov (United States)

    Poland, Michael P.; Jeff, Sutton A.; Gerlach, Terrence M.

    2009-01-01

    During mid-June 2007, the summit of Kīlauea Volcano, Hawai‘i, deflated rapidly as magma drained from the subsurface to feed an east rift zone intrusion and eruption. Coincident with the deflation, summit SO2 emission rates rose by a factor of four before decaying to background levels over several weeks. We propose that SO2 release was triggered by static decompression caused by magma withdrawal from Kīlauea's shallow summit reservoir. Models of the deflation suggest a pressure drop of 0.5–3 MPa, which is sufficient to trigger exsolution of the observed excess SO2 from a relatively small volume of magma at the modeled source depth beneath Kīlauea's summit. Static decompression may also explain other episodes of deflation accompanied by heightened gas emission, including the precursory phases of Kīlauea's 2008 summit eruption. Hazards associated with unexpected volcanic gas emission argue for increased awareness of magma reservoir pressure fluctuations.

  5. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC Education | GIS Inventory — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  6. GnRHa trigger for final oocyte maturation: is HCG trigger history?

    DEFF Research Database (Denmark)

    Humaidan, Peter; Alsbjerg, Birgit

    2014-01-01

    gonadotrophin (HCG) trigger. Early trials showed a severe luteal phase insufficiency after GnRHa trigger despite the application of standard luteal phase support protocols. Subsequent research has led to modifications of the luteal phase support, resulting in reproductive outcome comparable to that seen after...... HCG trigger in normal- and high-responders. GnRHa trigger facilitates a tailored approach to subsequent luteal phase support, taking into account the ovarian response to stimulation. In the future, GnRHa is likely to be used for trigger in all women co-treated with GnRH antagonists....

  7. Emission inventory; Inventaire des emissions

    Energy Technology Data Exchange (ETDEWEB)

    Fontelle, J.P. [CITEPA, Centre Interprofessionnel Technique d`Etudes de la Pollution Atmospherique, 75 - Paris (France)

    1997-12-31

    Statistics on air pollutant (sulfur dioxide, nitrogen oxides and ammonium) emissions, acid equivalent emissions and their evolution since 1990 in the various countries of Europe and the USA, are presented. Emission data from the industrial, agricultural, transportation and power sectors are given, and comparisons are carried out between countries based on Gnp and population, pollution import/export fluxes and compliance to the previous emission reduction objectives

  8. Upgrade of the CMS Global Muon Trigger

    CERN Document Server

    Jeitler, Manfred; Rabady, Dinyar; Sakulin, Hannes; Stahl, Achim

    2015-01-01

    The increase in center-of-mass energy and luminosity for Run-II of the Large Hadron Collider poses new challenges for the trigger systems of the experiments. To keep triggering with a similar performance as in Run-I, the CMS muon trigger is currently being upgraded. The new algorithms will provide higher resolution, especially for the muon transverse momentum and will make use of isolation criteria that combine calorimeter with muon information already in the level-1 trigger. The demands of the new algorithms can only be met by upgrading the level-1 trigger system to new powerful FPGAs with high bandwidth I/O. The processing boards will be based on the new μTCA standard. We report on the planned algorithms for the upgraded Global Muon Trigger (μGMT) which sorts and removes duplicates from boundaries of the muon trigger sub-systems. Furthermore, it determines how isolated the muon candidates are based on calorimetric energy deposits. The μGMT will be implemented using a processing board that features a larg...

  9. The ATLAS Electron and Photon Trigger

    CERN Document Server

    Jones, Samuel David; The ATLAS collaboration

    2018-01-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs boson. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based Level-1 trigger and a software-based high-level trigger, both of which were upgraded during the LHC shutdown in preparation for Run-2 operation. To cope with the increasing luminosity and more challenging pile-up conditions at a center-of-mass energy of 13 TeV, the trigger selections at each level are optimized to control the rates and keep efficiencies high. To achieve this goal multivariate analysis techniques are used. The ATLAS electron and photon triggers and their performance with Run 2 dat...

  10. The ATLAS Electron and Photon Trigger

    CERN Document Server

    Jones, Samuel David; The ATLAS collaboration

    2017-01-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs boson. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based Level-1 trigger and a software-based high-level trigger, both of which were upgraded during the LHC shutdown in preparation for Run-2 operation. To cope with the increasing luminosity and more challenging pile-up conditions at a center-of-mass energy of 13 TeV, the trigger selections at each level are optimized to control the rates and keep efficiencies high. To achieve this goal multivariate analysis techniques are used. The ATLAS electron and photon triggers and their performance with Run 2 dat...

  11. MMS observations of the Earth bow shock during magnetosphere compression and expansion: comparison of whistler wave properties around the shock ramp

    Science.gov (United States)

    Russell, C. T.; Strangeway, R. J.; Schwartz, S. J.

    2017-12-01

    The Magnetospheric Multiscale (MMS) spacecraft, with their state-of-the-art plasma and field instruments onboard, allow us to investigate electromagnetic waves at the bow shock and their association with small-scale disturbances in the shocked plasmas. Understanding these waves could improve our knowledge on the heating of electrons and ions across the shock ramp and the energy dissipation of supercritical shocks. We have found broad-band and narrow band waves across the shock ramp and slightly downstream. The broad-band waves propagate obliquely to the magnetic field direction and have frequencies up to the electron cyclotron frequency, while the narrow-band waves have frequencies of a few hundred Hertz, durations under a second, and are right-handed circularly polarized and propagate along the magnetic field lines. Both wave types are likely to be whistler mode with different generation mechanisms. When the solar wind pressure changes, MMS occasionally observed a pair of bow shocks when the magnetosphere was compressed and then expanded. We compare the wave observations under these two situations to understand their roles in the shock ramp as well as the upstream and downstream plasmas.

  12. The ATLAS level 2 trigger supervisor

    International Nuclear Information System (INIS)

    Abolins, M.; Blair, R. E.; Dawson, J. W.; Owen, D.; Pope, B. G.; Schlereth, J. L.; Weber dos Santos, R.

    1997-01-01

    This paper presents an overview of the hardware and software proposed for the ATLAS level 2 Trigger ROI Builder/Supervisor. The essential requirements of this system are that it operate at the design Level 1 Trigger rate of 100kHz and that it support the technical requirements of the architectures suggested for the ATLAS Level 2 Trigger. Commercial equipment and software support are used to the maximum extent possible, with support from dedicated hardware. Timing requirements and latencies are discussed and simulation results are presented

  13. The LHCb trigger in Run II

    CERN Document Server

    Michielin, Emanuele

    2016-01-01

    The LHCb trigger system has been upgraded to allow alignment, calibration and physics analysis to be performed in real time. An increased CPU capacity and improvements in the software have allowed lifetime unbiased selections of beauty and charm decays in the high level trigger. Thanks to offline quality event reconstruction already available online, physics analyses can be performed directly on this information and for the majority of charm physics selections a reduced event format can be written out. Beauty hadron decays are more efficiently triggered by re-optimised inclusive selections, and the HLT2 output event rate is increased by a factor of three.

  14. Electronic trigger for the ASP experiment

    International Nuclear Information System (INIS)

    Wilson, R.J.

    1985-11-01

    The Anomalous Single Photon (ASP) electronic trigger is described. The experiments is based on an electromagnetic calorimeter composed of arrays of lead glass blocks, read out with photo-multiplier tubes, surrounding the interaction point at the PEP storage ring. The primary requirement of the trigger system is to be sensitive to low energy (approx. =0.5 GeV and above) photons whilst discriminating against high backgrounds at PEP. Analogue summing of the PMT signals and a sequence of programmable digital look-up tables produces a ''dead-timeless'' trigger for the beam collision rate of 408 kHz. 6 refs., 6 figs

  15. Trigger tracking for the LHCb upgrade

    CERN Multimedia

    Dungs, K

    2014-01-01

    This poster presents a trigger system for the upgraded LHCb detector, scheduled to begin operation in 2020. The proposed trigger system is implemented entirely in software. We show that track reconstruction of a similar quality to that available in the offline algorithms can be performed on the full inelastic pp-collision rate. A track finding efficiency of 98.8% relative to offline can be achieved for good trigger tracks. The CPU time required for this reconstruction is less than 60% of the available budget.

  16. The CMS Barrel Muon trigger upgrade

    International Nuclear Information System (INIS)

    Triossi, A.; Sphicas, P.; Bellato, M.; Montecassiano, F.; Ventura, S.; Ruiz, J.M. Cela; Bedoya, C. Fernandez; Tobar, A. Navarro; Fernandez, I. Redondo; Ferrero, D. Redondo; Sastre, J.; Ero, J.; Wulz, C.; Flouris, G.; Foudas, C.; Loukas, N.; Mallios, S.; Paradas, E.; Guiducci, L.; Masetti, G.

    2017-01-01

    The increase of luminosity expected by LHC during Phase1 will impose tighter constraints for rate reduction in order to maintain high efficiency in the CMS Level1 trigger system. The TwinMux system is the early layer of the muon barrel region that concentrates the information from different subdetectors: Drift Tubes, Resistive Plate Chambers and Outer Hadron Calorimeter. It arranges the slow optical trigger links from the detector chambers into faster links (10 Gbps) that are sent in multiple copies to the track finders. Results from collision runs, that confirm the satisfactory operation of the trigger system up to the output of the barrel track finder, will be shown.

  17. Electronic trigger for the ASP experiment

    International Nuclear Information System (INIS)

    Wilson, R.J.

    1985-01-01

    The ASP electronic trigger is described. The experiment is based on an electromagnetic calorimeter composed of arrays of lead glass blocks, read out with photo-multiplier tubes, surrounding the interaction point at the PEP storage ring. The primary requirement of the trigger system is to be sensitive to low energy (≅ 0.5 GeV and above) photons whilst discriminating against high rate backgrounds at PEP. Analogue summing of the PMT signals and a sequence of programmable digital look-up tables produces a ''dead-timeless'' trigger for the beam collision rate of 408 kHz

  18. Long-term survey of lion-roar emissions inside the terrestrial magnetosheath obtained from the STAFF-SA measurements onboard the Cluster spacecraft

    Science.gov (United States)

    Pisa, D.; Krupar, V.; Kruparova, O.; Santolik, O.

    2017-12-01

    Intense whistler-mode emissions known as 'lion-roars' are often observed inside the terrestrial magnetosheath, where the solar wind plasma flow slows down, and the local magnetic field increases ahead of a planetary magnetosphere. Plasma conditions in this transient region lead to the electron temperature anisotropy, which can result in the whistler-mode waves. The lion-roars are narrow-band emissions with typical frequencies between 0.1-0.5 Fce, where Fce is the electron cyclotron frequency. We present results of a long-term survey obtained by the Spatio Temporal Analysis Field Fluctuations - Spectral Analyzer (STAFF-SA) instruments on board the four Cluster spacecraft between 2001 and 2010. We have visually identified the time-frequency intervals with the intense lion-roar signature. Using the Singular Value Decomposition (SVD) method, we analyzed the wave propagation properties. We show the spatial, frequency and wave power distributions. Finally, the wave properties as a function of upstream solar wind conditions are discussed.

  19. Galactic interaction as the trigger for the young radio galaxy MRC B1221-423

    OpenAIRE

    Anderson, Craig; Johnston, Helen; Hunstead, Richard

    2013-01-01

    Mergers between a massive galaxy and a small gas-rich companion (minor mergers) have been proposed as a viable mechanism for triggering radio emission in an active galaxy. Until now the problem has been catching this sequence of events as they occur. With MRC B1221$-$423 we have an active radio galaxy that has only recently been triggered, and a companion galaxy that provides the "smoking gun". Using spectroscopic data taken with the VIMOS Integral Field Unit detector on the European Southern...

  20. Triggered creep as a possible mechanism for delayed dynamic triggering of tremor and earthquakes

    Science.gov (United States)

    Shelly, David R.; Peng, Zhigang; Hill, David P.; Aiken, Chastity

    2011-01-01

    The passage of radiating seismic waves generates transient stresses in the Earth's crust that can trigger slip on faults far away from the original earthquake source. The triggered fault slip is detectable in the form of earthquakes and seismic tremor. However, the significance of these triggered events remains controversial, in part because they often occur with some delay, long after the triggering stress has passed. Here we scrutinize the location and timing of tremor on the San Andreas fault between 2001 and 2010 in relation to distant earthquakes. We observe tremor on the San Andreas fault that is initiated by passing seismic waves, yet migrates along the fault at a much slower velocity than the radiating seismic waves. We suggest that the migrating tremor records triggered slow slip of the San Andreas fault as a propagating creep event. We find that the triggered tremor and fault creep can be initiated by distant earthquakes as small as magnitude 5.4 and can persist for several days after the seismic waves have passed. Our observations of prolonged tremor activity provide a clear example of the delayed dynamic triggering of seismic events. Fault creep has been shown to trigger earthquakes, and we therefore suggest that the dynamic triggering of prolonged fault creep could provide a mechanism for the delayed triggering of earthquakes. ?? 2011 Macmillan Publishers Limited. All rights reserved.

  1. The Trigger Processor and Trigger Processor Algorithms for the ATLAS New Small Wheel Upgrade

    CERN Document Server

    Lazovich, Tomo; The ATLAS collaboration

    2015-01-01

    The ATLAS New Small Wheel (NSW) is an upgrade to the ATLAS muon endcap detectors that will be installed during the next long shutdown of the LHC. Comprising both MicroMegas (MMs) and small-strip Thin Gap Chambers (sTGCs), this system will drastically improve the performance of the muon system in a high cavern background environment. The NSW trigger, in particular, will significantly reduce the rate of fake triggers coming from track segments in the endcap not originating from the interaction point. We will present an overview of the trigger, the proposed sTGC and MM trigger algorithms, and the hardware implementation of the trigger. In particular, we will discuss both the heart of the trigger, an ATCA system with FPGA-based trigger processors (using the same hardware platform for both MM and sTGC triggers), as well as the full trigger electronics chain, including dedicated cards for transmission of data via GBT optical links. Finally, we will detail the challenges of ensuring that the trigger electronics can ...

  2. Trigger factors in migraine with aura

    DEFF Research Database (Denmark)

    Hauge, A W; Kirchmann, M; Olesen, J

    2010-01-01

    The aim of the present study was to identify trigger factors in migraine with aura (MA). A total of 629 MA patients representative of the Danish population were sent a questionnaire listing 16 trigger factors thought to be relevant as well as space for free text. Distinction was made between...... attacks with or without aura within each patient. The questionnaire was returned by 522 patients of whom 347 had current MA attacks. In total 80% with current attacks (278/347) indicated that at least one factor triggered their migraine, and 67% (187/278) in this group indicated that they were aware...... of at least one factor often or always giving rise to an attack of MA. Forty-one per cent (113/278) had co-occurring attacks of migraine without aura (MO). Stress (following stress), bright light, intense emotional influences, stress (during stress) and sleeping too much or too little were the trigger factors...

  3. Session summary: Electronics, triggering and data acquisition

    International Nuclear Information System (INIS)

    Rescia, S.

    1991-12-01

    The session focused on the requirements for calorimetry at the SSC/LHC. Results on new readout techniques, calibration, radiation hard electronics and semiconductor devices, analog and digital front and electronics, and trigger strategies are presented

  4. Performance of the CMS Level-1 Trigger

    CERN Document Server

    Brooke, James John

    2012-01-01

    The first level trigger of the CMS experiment is comprised of custom electronics that process data from the electromagnetic and hadron calorimeters and three technologies of muon detectors in order to select the most interesting events from LHC collisions, such as those consistent with the production and decay of the Higgs boson. The rate of events selected by this Level-1 trigger must be reduced from the beam crossing frequency to no more than 100 kHz further processing can occur, a major challenge since the LHC instantaneous luminosity has increased by six orders of magnitude since the start of operations to more than 6E33 cm-2s-1 today. The performance of the Level-1 trigger, in terms of rates and efficiencies of the main objects and trigger algorithms, as measured from LHC proton collisions at 7 and 8 TeV center-of-mass energies is presented here.

  5. SSC physics signatures and trigger requirements

    International Nuclear Information System (INIS)

    1985-01-01

    Strategies are considered for triggering on new physics processes on the environment of the SSC, where interaction rates will be very high and most new physics processes quite rare. The quantities available for use in the trigger at various levels are related to the signatures of possible new physics. Two examples were investigated in some detail using the ISAJET Monte Carlo program: Higgs decays to W pairs and a missing energy trigger applied to gluino pair production. In both of the examples studied in detail, it was found that workable strategies for reducing the trigger rate were obtainable which also produced acceptable efficiency for the processes of interest. In future work, it will be necessary to carry out such a program for the full spectrum of suggested new physics

  6. Developments of the ATLAS Jet Trigger

    CERN Document Server

    Lopes, L; The ATLAS collaboration

    2012-01-01

    There have been a lot of recent changes in the ATLAS jet trigger. The standard strategy, based on Regions Of Interest, is not well-suited for multi-jet events since it leads to pathologies and efficiency losses. This philosophy has been changed for the jet trigger, and we now have the possibility of unpacking the full calorimeter at Event Filter and (even for a small subset of the events) at an intermediate level between Level-1 and Level-2. We also moved to the use of calibrated scale at trigger level, and to the application of noise cuts to reduce rate spikes. We will present the performance of the jet trigger in 2011, when most of these changes were operational

  7. High-Power Triggered Gas Switches

    National Research Council Canada - National Science Library

    Giri, David

    1999-01-01

    .... There are several reasons to build triggered versions of the basic high-voltage spark gap. They include synchronization with an external event, timed-array antenna for steering directed energy systems etc...

  8. Tracking at High Level Trigger in CMS

    CERN Document Server

    Tosi, Mia

    2014-01-01

    A reduction of several orders of magnitude of the event rate is needed to reach values compatible with detector readout, offline storage and analysis capability. The CMS experiment has been designed with a two-level trigger system: the Level-1 Trigger (L1T), implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a trade-off between the complexity of the algorithms, the sustainable output rate, and the selection efficiency. With the computing power available during the 2012 data taking the maximum reconstruction time at HLT was about 200 ms per event, at the nominal L1T rate of 100 kHz. Track reconstruction algorithms are widely used in the HLT, for the reconstruction of the physics objects as well as in the identification of b-jets and lepton iso...

  9. Graphics Processing Units for HEP trigger systems

    Energy Technology Data Exchange (ETDEWEB)

    Ammendola, R. [INFN Sezione di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Bauce, M. [INFN Sezione di Roma “La Sapienza”, P.le A. Moro 2, 00185 Roma (Italy); University of Rome “La Sapienza”, P.lee A.Moro 2, 00185 Roma (Italy); Biagioni, A. [INFN Sezione di Roma “La Sapienza”, P.le A. Moro 2, 00185 Roma (Italy); Chiozzi, S.; Cotta Ramusino, A. [INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara (Italy); University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy); Fantechi, R. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); CERN, Geneve (Switzerland); Fiorini, M. [INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara (Italy); University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy); Giagu, S. [INFN Sezione di Roma “La Sapienza”, P.le A. Moro 2, 00185 Roma (Italy); University of Rome “La Sapienza”, P.lee A.Moro 2, 00185 Roma (Italy); Gianoli, A. [INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara (Italy); University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy); Lamanna, G., E-mail: gianluca.lamanna@cern.ch [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); INFN Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044 Frascati (Roma) (Italy); Lonardo, A. [INFN Sezione di Roma “La Sapienza”, P.le A. Moro 2, 00185 Roma (Italy); Messina, A. [INFN Sezione di Roma “La Sapienza”, P.le A. Moro 2, 00185 Roma (Italy); University of Rome “La Sapienza”, P.lee A.Moro 2, 00185 Roma (Italy); and others

    2016-07-11

    General-purpose computing on GPUs (Graphics Processing Units) is emerging as a new paradigm in several fields of science, although so far applications have been tailored to the specific strengths of such devices as accelerator in offline computation. With the steady reduction of GPU latencies, and the increase in link and memory throughput, the use of such devices for real-time applications in high-energy physics data acquisition and trigger systems is becoming ripe. We will discuss the use of online parallel computing on GPU for synchronous low level trigger, focusing on CERN NA62 experiment trigger system. The use of GPU in higher level trigger system is also briefly considered.

  10. Triggering and data acquisition general considerations

    International Nuclear Information System (INIS)

    Butler, Joel N.

    2003-01-01

    We provide a general introduction to trigger and data acquisition systems in High Energy Physics. We emphasize the new possibilities and new approaches that have been made possible by developments in computer technology and networking

  11. Compiler Strategies for Transport Triggered Architectures

    NARCIS (Netherlands)

    Janssen, J.

    2001-01-01

    Compiler technology plays an important role to enhance the performance of modern microprocessors. In this thesis, compiler techniques and strategies are described to enhance the performance of microprocessors based on the Transport Triggered Architecture. The interaction between two important phases

  12. CMS Developments for Track-Triggers

    CERN Document Server

    De Mattia, Marco

    2015-01-01

    The High Luminosity LHC (HL-LHC) is expected to deliver luminosities of 5$\\times10^{34}$cm$^{-2}$s$^{-1}$, with an average of about 140 overlapping proton-proton collisions per bunch crossing. These extreme pileup conditions place stringent requirements on the trigger system to be able to cope with the resulting event rates. A key component of the CMS upgrade for HL-LHC is a track trigger system which would identify tracks with transverse momentum above 2~\\,GeV already at the first-level trigger (L1). We present the status of proposals for implementing the L1 tracking in conjunction with the planned upgrade for the silicon tracker of the CMS experiment. The expected performance and the use of L1 tracks for triggering is discussed.

  13. Trigger circuits for the PHENIX electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Frank, S.S.; Britton, C.L. Jr.; Winterberg, A.L.; Young, G.R.

    1997-11-01

    Monolithic and discrete circuits have been developed to provide trigger signals for the PHENIX electromagnetic calorimeter detector. These trigger circuits are deadtimeless and create overlapping 4 by 4 energy sums, a cosmic muon trigger, and a 144 channel energy sum. The front end electronics of the PHENIX system sample the energy and timing channels at each bunch crossing (BC) but it is not known immediately if this data is of interest. The information from the trigger circuits is used to determine if the data collected is of interest and should be digitized and stored or discarded. This paper presents details of the design, issues affecting circuit performance, characterization of prototypes fabricated in 1.2 microm Orbit CMOS, and integration of the circuits into the EMCal electronics system

  14. D0 triggering and data acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Gibbard, B.

    1992-10-01

    The trigger for D0 is a multi-tier system. Within the 3.5 [mu]sec bunch crossing interval, custom electronics select interesting event candidates based on electromagnetic and hadronic energy deposits in the calorimeter and on indications of tracks in the muon system. Subsequent hardware decisions use refined calculations of electron and muon characteristics. The highest level trigger occurs in one element of a farm of microprocessors, where fully developed algorithms for electrons, muons, jets, or missing E[sub t] are executed. This highest level trigger also provides the assembly of the event into its final data structure. Performance of this trigger and data acquisition system in collider operation is described.

  15. Radio Follow-up of Gravitational-wave Triggers during Advanced LIGO O1

    Science.gov (United States)

    Palliyaguru, N. T.; Corsi, A.; Kasliwal, M. M.; Cenko, S. B.; Frail, D. A.; Perley, D. A.; Mishra, N.; Singer, L. P.; Gal-Yam, A.; Nugent, P. E.; Surace, J. A.

    2016-10-01

    We present radio follow-up observations carried out with the Karl G. Jansky Very Large Array during the first observing run (O1) of the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO). A total of three gravitational-wave triggers were followed-up during the ≈ 4 months of O1, from 2015 September to 2016 January. Two of these triggers, GW150914 and GW151226, are binary black hole (BH) merger events of high significance. A third trigger, G194575, was subsequently declared as an event of no interest (I.e., a false alarm). Our observations targeted selected optical transients identified by the intermediate Palomar Transient Factory in the Advanced LIGO error regions of the three triggers, and a limited region of the gravitational-wave localization area of G194575 not accessible to optical telescopes due to Sun constraints, where a possible high-energy transient was identified. No plausible radio counterparts to GW150914 and GW151226 were found, in agreement with expectations for binary BH mergers. We show that combining optical and radio observations is key to identifying contaminating radio sources that may be found in the follow-up of gravitational-wave triggers, such as emission associated with star formation and active galactic nuclei. We discuss our results in the context of the theoretical predictions for radio counterparts to gravitational-wave transients, and describe our future plans for the radio follow-up of Advanced LIGO (and Virgo) triggers.

  16. The new UA1 calorimeter trigger

    International Nuclear Information System (INIS)

    Eisenhandler, E.

    1988-01-01

    The new UA1 first-level calorimeter trigger processor is described, with emphasis on the fast two-dimensional electromagnetic cluster-finding that is its most novel feature. This processor is about five times more powerful than its predecessor, and makes extensive use of pipelining techniques. It allows multiple combinations of triggers on electromagnetic showers, hadronic jets and energy sums, including a total-energy veto of multiple interactions and a full vector sum of missing transverse energy. (author)

  17. A Gamma-Ray Burst Trigger Toolkit

    Science.gov (United States)

    Band, David L.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    The detection rate of a gamma-ray burst detector can be increased by using a count rate trigger with many accumulation times DELTAt and energy bands DELTAE Because a burst's peak flux varies when averaged over different DELTAt and DELTAE the nominal sensitivity (the numerical value of the peak flux) of a trigger system is less important than how much fainter a burst could be at the detection threshold as DELTAt and DELTAE are changed. The relative sensitivity of different triggers can be quantified by referencing the detection threshold back to the peak flux for a fiducial value of DELTAt and DELTA E. This mapping between peak flux values for different sets of DELTAt and DELTAE varies from burst to burst. Quantitative estimates of the burst detection rate for a given detector and trigger system can be based on the observed rate at a measured peak flux value in this fiducial trigger. Predictions of a proposed trigger's burst detection rate depend on the assumed burst population, and these predictions can be wildly in error for triggers that differ significantly from previous missions. I base the fiducial rate on the BATSE observations: 550 bursts per sky above a peak flux of 0.3 ph per square centimeter per second averaged over DELTAt=1.024 sec and DELTAE=50-300 keV. Using a sample of 100 burst lightcurves I find that triggering on any value of DELTAt that is a multiple of 0.064 sec decreases the average threshold peak flux on the 1.024 sec timescale by a factor of 0.6. Extending DELTAE to lower energies includes the large flux of the X-ray background, increasing the background count rate. Consequently a low energy DELTAE is advantageous only for very soft bursts. Whether a large fraction of the population of bright bursts is soft is disputed; the new population of X-ray Flashes is soft but relatively faint.

  18. The ALICE Central Trigger Processor (CTP) upgrade

    Czech Academy of Sciences Publication Activity Database

    Krivda, M.; Alexandre, D.; Barnby, L. S.; Evans, D.; Johnes, P. G.; Jusko, A.; Lietava, R.; Pospíšil, Jan; Baillie, O. V.

    2016-01-01

    Roč. 11, MAR (2016), C03051 ISSN 1748-0221. [Topical Workshop on Electronics for Particle Physics (TWEPP). Lisbon, 28.09.2015-02.10.2015] R&D Projects: GA MŠk(CZ) LG13031 Institutional support: RVO:61389005 Keywords : Trigger concepts and systems * Trigger algorithms * digital electronics circuits Subject RIV: JC - Computer Hardware ; Software Impact factor: 1.220, year: 2016

  19. Average Characteristics of Triggered and Nontriggered Substorms

    Science.gov (United States)

    Hsu, Tung-Shin; McPherron, Robert L.

    2004-01-01

    Magnetic field data from ground stations, geosynchronous orbit, and magnetotail are examined to study the response to substorm activity with and without apparent interplanetary magnetic field (IMF) perturbations. Global substorms are identified using a sudden, persistent decrease in the AL index. The onset of this global expansion is taken to be the time of the Pi2 burst nearest to the beginning of the AL decrease. IMF triggers were identified subjectively through visual scanning of the data. Both northward turnings of the IMF B, and decreases in the amplitude of the By component were considered as possible triggers. Two different solar wind monitors were used in the investigation: IMP 8 in a circular orbit with a distance between approx.12 and approx.35 R(sub E) from the Earth-Sun line and ISEE 2 in an elliptical orbit with a distance of only approx.5- 10 R(sub E) from the Earth-Sun line. The results of superposed epoch analysis show that the temporal response from ground stations, geosynchronous orbit, and magnetotail are nearly identical for triggered (with apparent IMF perturbation) and nontriggered (without apparent IMF perturbation) substorms. It is therefore concluded that the nontriggered substorms are not a different form of activity than triggered substorms. However, we demonstrate that the magnitude of the response is different for the two types of substo&. By every measure considered, triggered substorm are systematically larger than nontriggered substorms. We interpret the fact that nearly 40% of all substorms cannot be associated with an IMF trigger as evidence that substorms are caused by an internal instability. However, the fact that so many appear to be triggered suggests that this internal instability is susceptible to external perturbations by the IMF. The fact that triggered substorms are larger than nontriggered substorms is counterintuitive, and we have no explanation for the observation.

  20. LHCb Calorimeter from Trigger to Physics

    CERN Document Server

    Deschamps, O

    2004-01-01

    LHCb is a second generation experiment for CP violation study in B decays. It consists in a 20 meters long single-arm spectrometer to be installed on the future Large Hadron Collider at CERN. For its precision measurement purpose, it combines precise vertex location and particle identification, in addition with a per- formant trigger system able to cope with high flux. This document addresses the use of the calorimeter data for the LHCb trigger and the physics analyses.

  1. Elementary Steps in T Cell Receptor Triggering

    OpenAIRE

    Dushek, Omer

    2012-01-01

    The mechanism by which antigen binding to the T cell antigen receptor (TCR) generates intracellular signaling, a process termed TCR triggering, is incompletely understood. A large body of experimental evidence has implicated multiple biophysical/biochemical effects and multiple molecules in the process of TCR triggering, which likely reflect the uniquely demanding role of the TCR in recognizing diverse antigenic ligands. In this perspective, I propose that breaking down the process of TCR tri...

  2. Commissioning of the CMS High Level Trigger

    Energy Technology Data Exchange (ETDEWEB)

    Agostino, Lorenzo; et al.

    2009-08-01

    The CMS experiment will collect data from the proton-proton collisions delivered by the Large Hadron Collider (LHC) at a centre-of-mass energy up to 14 TeV. The CMS trigger system is designed to cope with unprecedented luminosities and LHC bunch-crossing rates up to 40 MHz. The unique CMS trigger architecture only employs two trigger levels. The Level-1 trigger is implemented using custom electronics, while the High Level Trigger (HLT) is based on software algorithms running on a large cluster of commercial processors, the Event Filter Farm. We present the major functionalities of the CMS High Level Trigger system as of the starting of LHC beams operations in September 2008. The validation of the HLT system in the online environment with Monte Carlo simulated data and its commissioning during cosmic rays data taking campaigns are discussed in detail. We conclude with the description of the HLT operations with the first circulating LHC beams before the incident occurred the 19th September 2008.

  3. Application of Vector Triggering Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

    This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented in this pa......This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented...... result is a Random Decrement function from each measurement. In traditional Random Decrement estimation the triggering condition is a scalar condition, which should only be fulfilled in a single measurement. In vector triggering Random Decrement the triggering condition is a vector condition....... The advantage of this new approach should be a reduction in estimation time without a significant loss of accuracy, since the vector triggering conditions ensure cross information between the measurements in the Random Decrement functions. The different problems with this technique is highlighted in two...

  4. Application of Vector Triggering Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

    1997-01-01

    This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented in this pa......This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented...... result is a Random Decrement function from each measurement. In traditional Random Decrement estimation the triggering condition is a scalar condition, which should only be fulfilled in a single measurement. In vector triggering Random Decrement the triggering condition is a vector condition....... The advantage of this new approach should be a reduction in estimation time without a significant loss of accuracy, since the vector triggering conditions ensure cross information between the measurements in the Random Decrement functions. The different problems with this technique is highlighted in two...

  5. Level-1 Calorimeter Trigger starts firing

    CERN Multimedia

    Stephen Hillier

    2007-01-01

    L1Calo is one of the major components of ATLAS First Level trigger, along with the Muon Trigger and Central Trigger Processor. It forms all of the first-level calorimeter-based triggers, including electron, jet, tau and missing ET. The final system consists of over 250 custom designed 9U VME boards, most containing a dense array of FPGAs or ASICs. It is subdivided into a PreProcessor, which digitises the incoming trigger signals from the Liquid Argon and Tile calorimeters, and two separate processor systems, which perform the physics algorithms. All of these are highly flexible, allowing the possibility to adapt to beam conditions and luminosity. All parts of the system are read out through Read-Out Drivers, which provide monitoring data and Region of Interest (RoI) information for the Level-2 trigger. Production of the modules is now essentially complete, and enough modules exist to populate the full scale system in USA15. Installation is proceeding rapidly - approximately 90% of the final modules are insta...

  6. Upgrade of the trigger system of CMS

    International Nuclear Information System (INIS)

    Jeitler, Manfred

    2013-01-01

    Various parts of the CMS trigger and in particular the Level-1 hardware trigger will be upgraded to cope with increasing luminosity, using more selective trigger conditions at Level 1 and improving the reliability of the system. Many trigger subsystems use FPGAs (Field Programmable Gate Arrays) in the electronics and will benefit from developments in this technology, allowing us to place much more logic into a single FPGA chip, thus reducing the number of chips, electronic boards and interconnections and in this way improving reliability. A number of subsystems plan to switch from the old VME bus to the new microTCA crate standard. Using similar approaches, identical modules and common software wherever possible will reduce costs and manpower requirements and improve the serviceability of the whole trigger system. The computer-farm based High-Level Trigger will not only be extended by using increasing numbers of more powerful PCs but there are also concepts for making it more robust and the software easier to maintain, which will result in better efficiency of the whole system

  7. Progress on the Level-1 Calorimeter Trigger

    CERN Multimedia

    Eric Eisenhandler

    The Level-1 Calorimeter Trigger (L1Calo) has recently passed a number of major hurdles. The various electronic modules that make up the trigger are either in full production or are about to be, and preparations in the ATLAS pit are well advanced. L1Calo has three main subsystems. The PreProcessor converts analogue calorimeter signals to digital, associates the rather broad trigger pulses with the correct proton-proton bunch crossing, and does a final calibration in transverse energy before sending digital data streams to the two algorithmic trigger processors. The Cluster Processor identifies and counts electrons, photons and taus, and the Jet/Energy-sum Processor looks for jets and also sums missing and total transverse energy. Readout drivers allow the performance of the trigger to be monitored online and offline, and also send region-of-interest information to the Level-2 Trigger. The PreProcessor (Heidelberg) is the L1Calo subsystem with the largest number of electronic modules (124), and most of its fu...

  8. The ATLAS trigger performance and evolution

    CERN Document Server

    Bartsch, V; The ATLAS collaboration

    2012-01-01

    During the data taking period from 2009 until 2012, the ATLAS trigger has been very successfully used to collect proton-proton data at LHC centre-of-mass energies between 900 GeV and 8 TeV at record breaking luminosities. The three level trigger system reduces the event rate from the design bunch crossing rate of up to 40 MHz to an average recording rate of about 300 Hz. Using custom electronics with input from the calorimeter and muon detectors, the first level rejects most background collisions in less than 2.5,$mu$s. Then follow two levels of software based triggers. The trigger system is designed to select events by identifying muons, electrons, photons, taus, jets, and B hadron candidates, as well as using global event signatures, such as missing transverse energy. The high trigger efficiencies illustrate that we have achieved a very good level of understanding of both the detector and trigger performance and successfully selected suitable streamed data samples for analysis.

  9. The ATLAS Trigger Performance and Evolution

    CERN Document Server

    Bartsch, V; The ATLAS collaboration

    2012-01-01

    During the data taking period from 2009 until 2012, the ATLAS trigger has been very successfully used to collect proton-proton data at LHC centre-of-mass energies between 900 GeV and 8 TeV at record breaking luminosities. The three‐level trigger system reduces the event rate from the design bunch‐crossing rate of 40 MHz to an average recording rate of about 300 Hz. Using custom electronics with input from the calorimeter and muon detectors, the first level rejects most background collisions in less than 2.5 μs. Then follow two levels of software‐based triggers. The trigger system is designed to select events by identifying muons, electrons, photons, taus, jets, and B hadron candidates, as well as using global event signatures, such as missing transverse energy. We give an overview of the strategy and performance of the different trigger selections during the 2011-2012 run. We also discuss the trigger evolution and redesign put in place to cope with the continuously rising luminosity and in particular t...

  10. Design studies for the Double Chooz trigger

    International Nuclear Information System (INIS)

    Cucoanes, Andi Sebastian

    2009-01-01

    The main characteristic of the neutrino mixing effect is assumed to be the coupling between the flavor and the mass eigenstates. Three mixing angles (θ 12 , θ 23 , θ 13 ) are describing the magnitude of this effect. Still unknown, θ 13 is considered very small, based on the measurement done by the CHOOZ experiment. A leading experiment will be Double Chooz, placed in the Ardennes region, on the same site as used by CHOOZ. The Double Chooz goal is the exploration of ∝80% from the currently allowed θ 13 region, by searching the disappearance of reactor antineutrinos. Double Chooz will use two similar detectors, located at different distances from the reactor cores: a near one at ∝150 m where no oscillations are expected and a far one at 1.05 km distance, close to the first minimum of the survival probability function. The measurement foresees a precise comparison of neutrino rates and spectra between both detectors. The detection mechanism is based on the inverse β-decay. The Double Chooz detectors have been designed to minimize the rate of random background. In a simplified view, two optically separated regions are considered. The target, filled with Gd-doped liquid scintillator, is the main antineutrino interaction volume. Surrounding the target, the inner veto region aims to tag the cosmogenic muon background which hits the detector. Both regions are viewed by photomultipliers. The Double Chooz trigger system has to be highly efficient for antineutrino events as well as for several types of background. The trigger analyzes discriminated signals from the central region and the inner veto photomultipliers. The trigger logic is fully programmable and can combine the input signals. The trigger conditions are based on the total energy released in event and on the PMT groups multiplicity. For redundancy, two independent trigger boards will be used for the central region, each of them receiving signals from half of the photomultipliers. A third trigger board

  11. Design studies for the Double Chooz trigger

    Energy Technology Data Exchange (ETDEWEB)

    Cucoanes, Andi Sebastian

    2009-07-24

    The main characteristic of the neutrino mixing effect is assumed to be the coupling between the flavor and the mass eigenstates. Three mixing angles ({theta}{sub 12}, {theta}{sub 23}, {theta}{sub 13}) are describing the magnitude of this effect. Still unknown, {theta}{sub 13} is considered very small, based on the measurement done by the CHOOZ experiment. A leading experiment will be Double Chooz, placed in the Ardennes region, on the same site as used by CHOOZ. The Double Chooz goal is the exploration of {proportional_to}80% from the currently allowed {theta}{sub 13} region, by searching the disappearance of reactor antineutrinos. Double Chooz will use two similar detectors, located at different distances from the reactor cores: a near one at {proportional_to}150 m where no oscillations are expected and a far one at 1.05 km distance, close to the first minimum of the survival probability function. The measurement foresees a precise comparison of neutrino rates and spectra between both detectors. The detection mechanism is based on the inverse {beta}-decay. The Double Chooz detectors have been designed to minimize the rate of random background. In a simplified view, two optically separated regions are considered. The target, filled with Gd-doped liquid scintillator, is the main antineutrino interaction volume. Surrounding the target, the inner veto region aims to tag the cosmogenic muon background which hits the detector. Both regions are viewed by photomultipliers. The Double Chooz trigger system has to be highly efficient for antineutrino events as well as for several types of background. The trigger analyzes discriminated signals from the central region and the inner veto photomultipliers. The trigger logic is fully programmable and can combine the input signals. The trigger conditions are based on the total energy released in event and on the PMT groups multiplicity. For redundancy, two independent trigger boards will be used for the central region, each of

  12. Evolution of Field-Aligned Electron and Ion Densities From Whistler Mode Radio Soundings During Quiet to Moderately Active Period and Comparisons With SAMI2 Simulations

    Science.gov (United States)

    Reddy, A.; Sonwalkar, V. S.; Huba, J. D.

    2018-02-01

    Knowledge of field-aligned electron and ion distributions is necessary for understanding the physical processes causing variations in field-aligned electron and ion densities. Using whistler mode sounding by Radio Plasma Imager/Imager for Magnetopause-to-Aurora Global Exploration (RPI/IMAGE), we determined the evolution of dayside electron and ion densities along L ˜ 2 and L ˜ 3 (90-4,000 km) during a 7 day (21-27 November 2005) geomagnetically quiet to moderately active period. Over this period the O+/H+ transition height was ˜880 ± 60 km and ˜1000 ± 100 km, respectively, at L ˜ 2 and L ˜ 3. The electron density varied in a complex manner; it was different at L ˜ 2 and L ˜ 3 and below and above the O+/H+ transition height. The measured electron and ion densities are consistent with those from Challenging Minisatellite Payload (CHAMP) and Defense Meteorological Satellite Program (DMSP) and other past measurements, but they deviated from bottomside sounding and International Reference Ionosphere (IRI) 2012 empirical model results. Using SAMI2 (Naval Research Laboratory (NRL) ionosphere model) with reasonably adjusted values of inputs (neutral densities, winds, electric fields, and photoelectron heating), we simulated the evolution of O+/H+ transition height and field-aligned electron and ion densities so that a fair agreement was obtained between the simulation results and observations. Simulation studies indicated that reduced neutral densities (H and/or O) with time limited O+-H charge exchange process. This reduction in neutral densities combined with changes in neutral winds and plasma temperature led to the observed variations in the electron and ion densities. The observation/simulation method presented here can be extended to investigate the role of neutral densities and composition, disturbed winds, and prompt penetration electric fields in the storm time ionosphere/plasmasphere dynamics.

  13. Synchronization of positive surface streamers triggered by vacuum ultraviolet in atmosphere

    International Nuclear Information System (INIS)

    Kashiwagi, Yasuhide; Itoh, Haruo

    2006-01-01

    The synchronous generation of the surface streamer discharges from two electrodes in air is investigated in terms of wavelength and intensity of the discharge light as a trigger for the synchronization of the surface streamers. It is found that the light emitted from the first streamer causes the photoelectron emission and the photoionization in the vicinity of the opposing electrode, triggering synchronous discharge of the second streamer. The wavelength of the light contributing to this phenomenon is shorter than 250 nm, with a remarkable rise in synchronization probability from 164 nm to 115 nm. This is considered to be due to the existence of the photoabsorption windows for oxygen in this vacuum ultraviolet region. These results suggest that the photon energy required to supply initial electrons sufficient to trigger the surface streamers on an acrylic resin insulator is at least 5 eV and more enhancement is found at 8 and 10 eV in this study

  14. ATLAS Trigger and DAQ Upgrades for High-Luminosity LHC

    Science.gov (United States)

    Ishino, M.

    2017-12-01

    The ATLAS Trigger-DAQ system will be significantly upgraded to explore new physics beyond the standard model in the High-Luminosity LHC environment with instantaneous luminosity of up to 7.5⨯1034cm-2 s-1. Two general trigger schemes are under study and their prospects and concerns are discussed. The muon trigger and readout electronics will be totally replaced to cope with a longer latency and a higher trigger rate. At the same time, new trigger algorithms using the precision tracker will be introduced to sharpen efficiency turn-ons and suppress fake triggers. The algorithm and the expected performance of the muon trigger are described. The hardware based track trigger is one of the major items introduced in the upgrade program. It will improve the trigger performance of various trigger items with a combination of the calorimeter or muon signature. The procedure for processing track information and an expected performance on the electron trigger are presented.

  15. Rate Predictions and Trigger/DAQ Resource Monitoring in ATLAS

    CERN Document Server

    Schaefer, D M; The ATLAS collaboration

    2012-01-01

    Since starting in 2010, the Large Hadron Collider (LHC) has pro- duced collisions at an ever increasing rate. The ATLAS experiment successfully records the collision data with high eciency and excel- lent data quality. Events are selected using a three-level trigger system, where each level makes a more re ned selection. The level-1 trigger (L1) consists of a custom-designed hardware trigger which seeds two higher software based trigger levels. Over 300 triggers compose a trig- ger menu which selects physics signatures such as electrons, muons, particle jets, etc. Each trigger consumes computing resources of the ATLAS trigger system and oine storage. The LHC instantaneous luminosity conditions, desired physics goals of the collaboration, and the limits of the trigger infrastructure determine the composition of the ATLAS trigger menu. We describe a trigger monitoring frame- work for computing the costs of individual trigger algorithms such as data request rates and CPU consumption. This framework has been used...

  16. CMS Triggers for the LHC Startup

    CERN Document Server

    Nhan Nguyen, Chi

    2009-01-01

    The LHC will collide proton beams at a bunch-crossing rate of 40 MHz. At the design luminosity of $10^{34}$ cm$^{-2}$s$^{-1}$ each crossing results in an average of about 20 inelastic pp events. The CMS trigger system is designed to reduce the input rate to about 100 Hz. This task is carried out in two steps, namely the Level-1 (L1) and the High-Level trigger (HLT). The L1 trigger is built of customized fast electronics and is designed to reduce the rate to 100 kHz. The HLT is implemented in a filter farm running on hundreds of CPUs and is designed to reduce the rate by another factor of ~1000. It combines the traditional L2 and L3 trigger components in a novel way and allows the coherent tuning of the HLT algorithms to accommodate multiple physics channels. We will discuss the strategies for optimizing triggers covering the experiment`s early physics program.

  17. DZERO Level 3 DAQ/Trigger Closeout

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The Tevatron Collider, located at the Fermi National Accelerator Laboratory, delivered its last 1.96 TeV proton-antiproton collisions on September 30th, 2011. The DZERO experiment continues to take cosmic data for final alignment for several more months . Since Run 2 started, in March 2001, all DZERO data has been collected by the DZERO Level 3 Trigger/DAQ System. The system is a modern, networked, commodity hardware trigger and data acquisition system based around a large central switch with about 60 front ends and 200 trigger computers. DZERO front end crates are VME based. Single Board Computer interfaces between detector data on VME and the network transport for the DAQ system. Event flow is controlled by the Routing Master which can steer events to clusters of farm nodes based on the low level trigger bits that fired. The farm nodes are multi-core commodity computer boxes, without special hardware, that run isolated software to make the final Level 3 trigger decision. Passed events are transferred to th...

  18. Software Validation Infrastructure for the ATLAS Trigger

    CERN Document Server

    Adorisio, C; Beauchemin, P; Bell, P; Biglietti, M; Coccaro, A; Damazio, D; Ehrenfeld, W; Faulkner, P; George, S; Giagu, S; Goncalo, R; Hamilton, A; Jones, G; Kirk, J; Kwee, R; Lane, J; Enoque Ferreira de Lima, D; Masik, J; Mincer, A; Monticelli, F; Omachi, C; Oyarzun, A; Panikashvili, N; Potter, C; Quinonez, F; Reinsch, A; Robinson, M; Rodríguez, D; Sarkisyan-Grinbaum, E; Sidoti, A; Sinev, N; Strom, D; Sutton, M; Ventura, A; Winklmeier, F; Zhao, L

    2009-01-01

    The ATLAS trigger system is responsible for selecting the interesting collision events delivered by the Large Hadron Collider (LHC). The ATLAS trigger will need to achieve a ~10^-7 rejection factor against random proton-proton collisions, and still be able to efficiently select interesting events. After a first processing level based on hardware, the final event selection is based on custom software running on two CPU farms, containing around two thousand multi-core machines. This is known as the high-level trigger. Running the trigger online during long periods demands very high quality software. It must be fast, performant, and essentially bug-free. With more than 100 contributors and around 250 different packages, a thorough validation of the HLT software is essential. This relies on a variety of unit and integration tests as well as on software metrics, and uses both in-house and open source software. This presentation presents the existing infrastructure used for validating the high-level trigger softwar...

  19. The CMS trigger in Run 2

    CERN Document Server

    Tosi, Mia

    2018-01-01

    During its second period of operation (Run 2) which started in 2015, the LHC will reach a peak instantaneous luminosity of approximately 2$\\times 10^{34}$~cm$^{-2}s^{-1}$ with an average pile-up of about 55, far larger than the design value. Under these conditions, the online event selection is a very challenging task. In CMS, it is realised by a two-level trigger system: the Level-1 (L1) Trigger, implemented in custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the offline reconstruction software running on a computer farm.\\\\ In order to face this challenge, the L1 trigger has undergone a major upgrade compared to Run 1, whereby all electronic boards of the system have been replaced, allowing more sophisticated algorithms to be run online. Its last stage, the global trigger, is now able to perform complex selections and to compute high-level quantities, like invariant masses. Likewise, the algorithms that run in the HLT went through big improvements; in particular, new ap...

  20. Validation of ATLAS L1 Topological Triggers

    CERN Document Server

    Praderio, Marco

    2017-01-01

    The Topological trigger (L1Topo) is a new component of the ATLAS L1 (Level-1) trigger. Its purpose is that of reducing the otherwise too high rate of data collection from the LHC by rejecting those events considered “uninteresting” (meaning that they have already been studied). This event rate reduction is achieved by applying topological requirements to the physical objects present in each event. It is very important to make sure that this trigger does not reject any “interesting” event. Therefore we need to verify its correct functioning. The goal of this summer student project is to study the response of two L1Topo algorithms (concerning ∆R and invariant mass). To do so I will compare the trigger decisions produced by the L1Topo hardware with the ones produced by the “official” L1Topo simulation. This way I will be able to identify events that could be incorrectly rejected. Simultaneously I will produce an emulation of these triggers that will help me understand the cause of disagreements bet...

  1. Tracking at High Level Trigger in CMS

    CERN Document Server

    Tosi, Mia

    2016-01-01

    The trigger systems of the LHC detectors play a crucial role in determining the physics capabili- ties of the experiments. A reduction of several orders of magnitude of the event rate is needed to reach values compatible with detector readout, offline storage and analysis capability. The CMS experiment has been designed with a two-level trigger system: the Level-1 Trigger (L1T), implemented on custom-designed electronics, and the High Level Trigger (HLT), a stream- lined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a trade-off between the complexity of the algorithms, the sustainable out- put rate, and the selection efficiency. With the computing power available during the 2012 data taking the maximum reconstruction time at HLT was about 200 ms per event, at the nominal L1T rate of 100 kHz. Track reconstruction algorithms are widely used in the HLT, for the reconstruction of the physics objects as well as in the identification of b-jets and ...

  2. The Fast Interaction Trigger Upgrade for ALICE

    CERN Document Server

    Garcia-Solis, Edmundo

    2016-01-01

    The ALICE Collaboration is preparing a major detector upgrade for the second LHC long shutdown (2019–20). The LHC heavy-ion luminosity and collision rate from 2021 onwards will considerably exceed the design parameters of the present ALICE forward trigger detectors. Furthermore, the introduction of a new Muon Forward Tracker (MFT) will significantly reduce the space available for the upgraded trigger detectors. To comply with these conditions a Fast Interaction Trigger (FIT) has been designed. FIT will be the primary forward trigger, luminosity, and collision time measurement detector. The FIT will be capable of triggering at an interaction rate of 50 kHz, with a time resolution better than 30 ps, with 99% efficiency. It will also determine multiplicity, centrality, and reaction plane. FIT will consist of two arrays of Cherenkov radiators with MCP-PMT sensors and of a single, large-size scintillator ring. The arrays will be placed on both sides of the interaction point (IP). Because of the presence of the h...

  3. Upgrades of the ATLAS trigger system

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00221618; The ATLAS collaboration

    2018-01-01

    In coming years the LHC is expected to undergo upgrades to increase both the energy of proton-proton collisions and the instantaneous luminosity. In order to cope with these more challenging LHC conditions, upgrades of the ATLAS trigger system will be required. This talk will focus on some of the key aspects of these upgrades. Firstly, the upgrade period between 2019-2021 will see an increase in instantaneous luminosity to $3\\times10^{34} \\rm{cm^{-2}s^{-1}}$. Upgrades to the Level 1 trigger system during this time will include improvements for both the muon and calorimeter triggers. These include the upgrade of the first-level Endcap Muon trigger, the calorimeter trigger electronics and the addition of new calorimeter feature extractor hardware, such as the Global Feature Extractor (gFEX). An overview will be given on the design and development status the aforementioned systems, along with the latest testing and validation results. \\\\ By 2026, the High Luminosity LHC will be able to deliver 14 TeV collisions ...

  4. The ZEUS calorimeter first level trigger

    Science.gov (United States)

    Silverstein, S.; Ali, I.; Behrens, B.; Foudas, C.; Fordham, C.; Goussiou, A.; Jaworski, M.; Lackey, J.; Reeder, D.; Robl, P.; Smith, W. H.; Vaiciulis, A.; Wodarczyk, M.; Dawson, J.; Krakauer, D.; Talaga, R.; Schlereth, J.; Zhang, H.

    1995-02-01

    An overview of the ZEUS calorimeter first level trigger is presented. The CFLT uses a pipelined architecture to accept and analyze calorimeter data for every 96 ns beam crossing interval. PMT signals are combined by analog electronics into electromagnetic and hadronic sums for 896 trigger towers. The analog sums are then digitized and analyzed. The CFLT determines the total, transverse, and missing transverse energy, identifies isolated electrons and muons, and sums energies in programmable subregions. Calculations are performed in 96 ns steps, and new data are accepted for every beam crossing. Trigger data are forwarded to the global first level trigger (GFLT) after 2 μs, allowing a GFLT accept to be issued 5 μs after the beam crossing which produced the event. Important features of the CFLT include a 12-bit effective dynamic range, extensive use of memory lookup tables for trigger calculations, fast pattern searches for isolated leptons, and low electronics noise. During the 1993 HERA run, the CFLT reduced a 50 kHz background rate to around 100 Hz.

  5. Graphical processors for HEP trigger systems

    Energy Technology Data Exchange (ETDEWEB)

    Ammendola, R. [INFN Sezione di Roma Tor Vergata, Via della Ricerca Scientifica, 1, 00133 Roma (Italy); Biagioni, A. [INFN Sezione di Roma, P.le Aldo Moro, 2, 00185 Roma (Italy); Chiozzi, S.; Cotta Ramusino, A. [INFN Sezione di Ferrara, Via Saragat, 1, 44122 Ferrara (Italy); Di Lorenzo, S. [INFN Sezione di Pisa, L. Bruno Pontecorvo, 3, 56127 Pisa (Italy); Università di Pisa, Lungarno Pacinotti 43, 56126 Pisa (Italy); Fantechi, R. [INFN Sezione di Pisa, L. Bruno Pontecorvo, 3, 56127 Pisa (Italy); Fiorini, M. [INFN Sezione di Ferrara, Via Saragat, 1, 44122 Ferrara (Italy); Università di Ferrara, Via Ludovico Ariosto 35, 44121 Ferrara (Italy); Frezza, O. [INFN Sezione di Roma, P.le Aldo Moro, 2, 00185 Roma (Italy); Lamanna, G. [INFN, Laboratori Nazionali di Frascati (Italy); Lo Cicero, F.; Lonardo, A.; Martinelli, M.; Neri, I.; Paolucci, P.S.; Pastorelli, E. [INFN Sezione di Roma, P.le Aldo Moro, 2, 00185 Roma (Italy); Piandani, R. [INFN Sezione di Pisa, L. Bruno Pontecorvo, 3, 56127 Pisa (Italy); Pontisso, L., E-mail: luca.pontisso@cern.ch [INFN Sezione di Pisa, L. Bruno Pontecorvo, 3, 56127 Pisa (Italy); Rossetti, D. [NVIDIA Corp., Santa Clara, CA (United States); Simula, F. [INFN Sezione di Roma, P.le Aldo Moro, 2, 00185 Roma (Italy); Sozzi, M. [INFN Sezione di Pisa, L. Bruno Pontecorvo, 3, 56127 Pisa (Italy); Università di Pisa, Lungarno Pacinotti 43, 56126 Pisa (Italy); and others

    2017-02-11

    General-purpose computing on GPUs is emerging as a new paradigm in several fields of science, although so far applications have been tailored to employ GPUs as accelerators in offline computations. With the steady decrease of GPU latencies and the increase in link and memory throughputs, time is ripe for real-time applications using GPUs in high-energy physics data acquisition and trigger systems. We will discuss the use of online parallel computing on GPUs for synchronous low level trigger systems, focusing on tests performed on the trigger of the CERN NA62 experiment. Latencies of all components need analysing, networking being the most critical. To keep it under control, we envisioned NaNet, an FPGA-based PCIe Network Interface Card (NIC) enabling GPUDirect connection. Moreover, we discuss how specific trigger algorithms can be parallelised and thus benefit from a GPU implementation, in terms of increased execution speed. Such improvements are particularly relevant for the foreseen LHC luminosity upgrade where highly selective algorithms will be crucial to maintain sustainable trigger rates with very high pileup.

  6. Tools for Trigger Rate Monitoring at CMS

    CERN Document Server

    Smith, Geoffrey; Wightman, Andrew Steven

    2017-01-01

    In 2017, we expect the LHC to deliver an instantaneous luminosity of roughly $2.0 \\times 10^{34}$~cm$^{-2}$s$^{-1}$ to the Compact Muon Solenoid (CMS) experiment, with about 60 simultaneous proton-proton collisions (pileup) per event. In these challenging conditions, it is important to be able to intelligently monitor the rate at which data are being collected (the trigger rate). It is not enough to simply look at the trigger rate; it is equally important to compare the trigger rate with expectations. We present a set of software tools that have been developed to accomplish this. The tools include a real-time component - a script that monitors the rates of individual triggers during data-taking, and activates an alarm if rates deviate significantly from expectation. Fits are made to previously collected data and extrapolated to higher pileup. The behavior of triggers as a function of pileup is then monitored as data are collected - plots are automatically produced on an hourly basis and uploaded to a web area...

  7. Emission spectroscopy

    International Nuclear Information System (INIS)

    Barnes, R.M.

    1978-01-01

    This 16th article in the series of biennial reviews of emission spectroscopy surveys with emphasis the emission spectrochemical literature appearing in referred publications during 1976 and 1977. Books and general reviews of emission spectroscopy and closely related subjects are considered in the first section, whereas specific reviews and texts are included in each of the five tropical sections. Spectral descriptions and classifications are examined in the second section. An abbreviated instrumentation section follows, and standards, samples, calibrations, and calculations are evaluated in the fourth section. The emphasis on excitation sources reflects the size of section five. In the sixth section, important applications are explored

  8. Software for implementing trigger algorithms on the upgraded CMS Global Trigger System

    CERN Document Server

    Matsushita, Takashi

    2015-01-01

    The Global Trigger is the final step of the CMS Level-1 Trigger andimplements a trigger menu, a set of selection requirements applied tothe final list of trigger objects. The conditions for trigger objectselection, with possible topological requirements on multi-object triggers,are combined by simple combinatorial logic to form the algorithms.The LHC has resumed its operation in 2015, the collision-energy will beincreased to 13~TeV with the luminosity expected to go upto~2$\\times$10$^{34}$~cm$^{-2}$s$^{-1}$. The CMS Level-1 trigger systemwill be upgraded to improve its performance for selecting interestingphysics events and to operate within the predefined data-acquisition ratein the challenging environment expected at LHC Run~2.The Global Trigger will be re-implemented on modern FPGAs on an AdvancedMezzanine Card in MicroTCA crate. The upgraded system will benefit fromthe ability to process complex algorithms with DSP slices and increasedprocessing resources with optical links running at~10 Gbit/s, enablingm...

  9. Performance of the ATLAS Muon Trigger and Phase-1 Upgrade of Level-1 Endcap Muon Trigger

    CERN Document Server

    Mizukami, Atsushi; The ATLAS collaboration

    2017-01-01

    The ATLAS experiment utilises a trigger system to efficiently record interesting events. It consists of first-level and high-level triggers. The first-level trigger is implemented with custom-built hardware to reduce the event rate from 40 MHz to100 kHz. Then the software-based high-level triggers refine the trigger decisions reducing the output rate down to 1 kHz. Events with muons in the final state are an important signature for many physics topics at the LHC. An efficient trigger on muons and a detailed understanding of its performance are required. Trigger efficiencies are, for example, obtained from the muon decay of Z boson, with a Tag&Probe method, using proton-proton collision data collected in 2016 at a centre-of-mass energy of 13 TeV. The LHC is expected to increase its instantaneous luminosity to $3\\times10^{34} \\rm{cm^{-2}s^{-1}}$ after the phase-1 upgrade between 2018-2020. The upgrade of the ATLAS trigger system is mandatory to cope with this high-luminosity. In the phase-1 upgrade, new det...

  10. A new fast and programmable trigger logic

    International Nuclear Information System (INIS)

    Fucci, A.; Amendolia, S.R.; Bertolucci, E.; Bottigli, U.; Bradaschia, C.; Foa, L.; Giazotto, A.; Giorgi, M.; Givoletti, M.; Lucardesi, P.; Menzione, A.; Passuello, D.; Quaglia, M.; Ristori, L.; Rolandi, L.; Salvadori, P.; Scribano, A.; Stanga, R.; Stefanini, A.; Vincelli, M.L.

    1977-01-01

    The NA1 (FRAMM) experiment, under construction for the CERN-SPS North Area, deals with more than 1000 counter signals which have to be combined together in order to build sophisticated and highly selective triggers. These requirements have led to the development of a low cost, combinatorial, fast electronics which can replace, in an advantageous way the standard NIM electronics at the trigger level. The essential performances of the basic circuit are: 1) programmability of any desired logical expression; 2) trigger time independent of the chosen expression; 3) reduced cost and compactness due to the use of commercial RAMs, PROMs, and PLAs; 4) short delay, less than 20 ns, between input and output pulses. (Auth.)

  11. A self triggered intensified Ccd (Stic)

    International Nuclear Information System (INIS)

    Charon, Y.; Laniece, P.; Bendali, M.

    1990-01-01

    We are developing a new device based on the results reported previously of the successfull coincidence detection of β- particles with a high spatial resolution [1]. The novelty of the device consists in triggering an intensified CCD, i.e. a CCD coupled to an image intensifier (II), by an electrical signal collected from the II itself. This is a suitable procedure for detecting with high efficiency and high resolution low light rare events. The trigger pulse is obtained from the secondary electrons produced by multiplication in a double microchannel plate (MCP) and collected on the aluminized layer protecting the phosphor screen in the II. Triggering efficiencies up to 80% has been already achieved

  12. The UA1 upgrade calorimeter trigger processor

    International Nuclear Information System (INIS)

    Bains, M.; Charleton, D.; Ellis, N.; Garvey, J.; Gregory, J.; Jimack, M.P.; Jovanovic, P.; Kenyon, I.R.; Baird, S.A.; Campbell, D.; Cawthraw, M.; Coughlan, J.; Flynn, P.; Galagedera, S.; Grayer, G.; Halsall, R.; Shah, T.P.; Stephens, R.; Biddulph, P.; Eisenhandler, E.; Fensome, I.F.; Landon, M.; Robinson, D.; Oliver, J.; Sumorok, K.

    1990-01-01

    The increased luminosity of the improved CERN Collider and the more subtle signals of second-generation collider physics demand increasingly sophisticated triggering. We have built a new first-level trigger processor designed to use the excellent granularity of the UA1 upgrade calorimeter. This device is entirely digital and handles events in 1.5 μs, thus introducing no dead time. Its most novel feature is fast two-dimensional electromagnetic cluster-finding with the possibility of demanding an isolated shower of limited penetration. The processor allows multiple combinations of triggers on electromagnetic showers, hadronic jets and energy sums, including a total-energy veto of multiple interactions and a full vector sum of missing transverse energy. This hard-wired processor is about five times more powerful than its predecessor, and makes extensive use of pipelining techniques. It was used extensively in the 1988 and 1989 runs of the CERN Collider. (orig.)

  13. BTeV trigger/DAQ innovations

    Energy Technology Data Exchange (ETDEWEB)

    Votava, Margaret; /Fermilab

    2005-05-01

    BTeV was a proposed high-energy physics (HEP) collider experiment designed for the study of B-physics and CP Violation at the Tevatron at Fermilab. BTeV included a large-scale, high-speed trigger and data acquisition (DAQ) system, reading data from the detector at 500 Gbytes/sec and writing data to mass storage at a rate of 200 Mbytes/sec. The design of the trigger/DAQ system was innovative while remaining realistic in terms of technical feasibility, schedule and cost. This paper will give an overview of the BTeV trigger/DAQ architecture, highlight some of the technical challenges, and describe the approach that was used to solve these challenges.

  14. Trigger segments: towards improving listening skills?

    Science.gov (United States)

    Menahem, S

    1988-05-01

    Written 'trigger' segments depicting emotionally charged clinical situations arising from real patient encounters, and ending with a pertinent statement by the parent, were prepared and presented to senior medical students, postgraduate medical and allied professionals. They were asked to record their immediate reactions, how they would have responded and on reflection, how they ought to have responded. General discussion followed, highlighting various issues dealing with patient management. Trigger segments, a relatively simple teaching approach, allow students to experience difficult clinical situations and learn, in a relatively supportive environment of their peers, their own responses. Such triggers as part of a wider programme, may provide a further method to improve listening skills and increase personal understanding of the professional's own responses.

  15. The double Chooz hardware trigger system

    Energy Technology Data Exchange (ETDEWEB)

    Cucoanes, Andi; Beissel, Franz; Reinhold, Bernd; Roth, Stefan; Stahl, Achim; Wiebusch, Christopher [RWTH Aachen (Germany)

    2008-07-01

    The double Chooz neutrino experiment aims to improve the present knowledge on {theta}{sub 13} mixing angle using two similar detectors placed at {proportional_to}280 m and respectively 1 km from the Chooz power plant reactor cores. The detectors measure the disappearance of reactor antineutrinos. The hardware trigger has to be very efficient for antineutrinos as well as for various types of background events. The triggering condition is based on discriminated PMT sum signals and the multiplicity of groups of PMTs. The talk gives an outlook to the double Chooz experiment and explains the requirements of the trigger system. The resulting concept and its performance is shown as well as first results from a prototype system.

  16. Dendrite Injury Triggers DLK-Independent Regeneration

    Directory of Open Access Journals (Sweden)

    Michelle C. Stone

    2014-01-01

    Full Text Available Axon injury triggers regeneration through activation of a conserved kinase cascade, which includes the dual leucine zipper kinase (DLK. Although dendrites are damaged during stroke, traumatic brain injury, and seizure, it is not known whether mature neurons monitor dendrite injury and initiate regeneration. We probed the response to dendrite damage using model Drosophila neurons. Two larval neuron types regrew dendrites in distinct ways after all dendrites were removed. Dendrite regeneration was also triggered by injury in adults. Next, we tested whether dendrite injury was initiated with the same machinery as axon injury. Surprisingly, DLK, JNK, and fos were dispensable for dendrite regeneration. Moreover, this MAP kinase pathway was not activated by injury to dendrites. Thus, neurons respond to dendrite damage and initiate regeneration without using the conserved DLK cascade that triggers axon regeneration.

  17. Combining triggers in HEP data analysis

    International Nuclear Information System (INIS)

    Lendermann, Victor; Herbst, Michael; Krueger, Katja; Schultz-Coulon, Hans-Christian; Stamen, Rainer; Haller, Johannes

    2009-01-01

    Modern high-energy physics experiments collect data using dedicated complex multi-level trigger systems which perform an online selection of potentially interesting events. In general, this selection suffers from inefficiencies. A further loss of statistics occurs when the rate of accepted events is artificially scaled down in order to meet bandwidth constraints. An offline analysis of the recorded data must correct for the resulting losses in order to determine the original statistics of the analysed data sample. This is particularly challenging when data samples recorded by several triggers are combined. In this paper we present methods for the calculation of the offline corrections and study their statistical performance. Implications on building and operating trigger systems are discussed. (orig.)

  18. A self triggered intensified CCD (STIC)

    Science.gov (United States)

    Charon, Y.; Laniece, P.; Bendali, M.; Gaillard, J. M.; Leblanc, M.; Mastrippolito, R.; Tricoire, H.; Valentin, L.

    1991-12-01

    We are developing a new device based on the results reported previously of the successful coincidence detection of β - particles with a high spatial resolution. The novelty of the device consists in triggering and intensified CCD, i.e. a CCD coupled to an image intensifier (II), by an electrical signal collected from the II itself. This is a suitable procedure for detecting low light and rare events with high efficiency and high resolution. The trigger pulse is obtained from the secondary electrons produced by multiplication in a double microchannel plate (MCP) and collected on the aluminized layer protecting the phosphor screen in the II. Triggering efficiencies up to 80% have already been achieved.

  19. Self-triggering superconducting fault current limiter

    Science.gov (United States)

    Yuan, Xing [Albany, NY; Tekletsadik, Kasegn [Rexford, NY

    2008-10-21

    A modular and scaleable Matrix Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. The matrix fault current limiter comprises a fault current limiter module that includes a superconductor which is electrically coupled in parallel with a trigger coil, wherein the trigger coil is magnetically coupled to the superconductor. The current surge doing a fault within the electrical power network will cause the superconductor to transition to its resistive state and also generate a uniform magnetic field in the trigger coil and simultaneously limit the voltage developed across the superconductor. This results in fast and uniform quenching of the superconductors, significantly reduces the burnout risk associated with non-uniformity often existing within the volume of superconductor materials. The fault current limiter modules may be electrically coupled together to form various "n" (rows).times."m" (columns) matrix configurations.

  20. Alcoholic drinks as triggers in primary headaches.

    Science.gov (United States)

    Panconesi, Alessandro; Franchini, Michela; Bartolozzi, Maria Letizia; Mugnai, Stefania; Guidi, Leonello

    2013-08-01

    This project aims to investigate the role of alcoholic drinks (ADs) as triggers for primary headaches. Patients followed in the Headache Centre and presenting with migraine without aura, migraine with aura (MA), chronic migraine (CM), and tension-type headache (TH) were asked if their headache was precipitated by AD and also about their alcohol habits. Individual characteristics and drink habits were evaluated within two binary logistic models. About one half (49.7%) of patients were abstainers, 17.6% were habitual consumers, and 32.5% were occasional consumers. Out of 448 patients, only 22 (4.9%), all with migraine, reported AD as a trigger factor. None of 44 patients with MA and none of 47 patients with TH reported AD as a trigger factor. Among those patients with migraine who consume AD, only 8% reported that AD can precipitate their headache. Multivariate analyses showed that AD use, both occasional and habitual, is unrelated to TH. Moreover, analysis performed among migraine patients, points out that occasional and habitual drinkers have a lower risk of presenting with CM than abstainers, although statistical significance occurred only among occasional drinkers. Only 3% of migraine patients who abstain from AD reported that they do not consume alcohol because it triggers their headache. Our study shows that AD acts as headache triggers in a small percentage of migraine patients. Differing from some prior studies, our data suggest that AD do not trigger MA and TH attacks. Moreover, the percentage of abstainers in our sample is higher compared with that reported in general population surveys. Wiley Periodicals, Inc.

  1. The ZEUS second level calorimeter trigger

    International Nuclear Information System (INIS)

    Jong, S.J. de.

    1990-01-01

    ZEUS is a detector for the HERA ep collider, consisting of several large components. The most important being the inner tracking detectors, which are positioned nearest to the interaction point, the calorimeter surrounding the inner tracking detectors and the muon detectors on the outside of the experimental setup. Each component will deliver a vast amount of information. In order to keep this information manageable, data is preprocessed and condensed per component and then combined to obtain the final global trigger result. The main subject of this thesis is the second level calorimeter trigger processor of the ZEUS detector. In order to be able to reject the unwanted events passing the first level, the topological event signature will have to be used at the second level. The most demanding task of the second level is the recognition of local energy depositions corresponding to isolated electrons and hadron jets. Also part of the work performed by the first level will be repeated with a higher level of accuracy. Additional information not available to the first level trigger will be processed and will be made available to the global second level trigger decision module. For the second level calorimeter trigger processor a special VME module, containing two transputers, has been developed. The second level calorimeter trigger algorithm described in this thesis was tested with simulated events, that were tracked through a computer simulation of the ZEUS detector. A part of this thesis is therefore devoted to the description of the various Monte Carlo models and the justification of the way in which they were used. (author). 132 refs.; 76 figs.; 18 tabs

  2. The ATLAS trigger: high-level trigger commissioning and operation during early data taking

    International Nuclear Information System (INIS)

    Goncalo, R

    2008-01-01

    The ATLAS experiment is one of the two general-purpose experiments due to start operation soon at the Large Hadron Collider (LHC). The LHC will collide protons at a centre of mass energy of 14 TeV, with a bunch-crossing rate of 40 MHz. The ATLAS three-level trigger will reduce this input rate to match the foreseen offline storage capability of 100-200 Hz. This paper gives an overview of the ATLAS High Level Trigger focusing on the system design and its innovative features. We then present the ATLAS trigger strategy for the initial phase of LHC exploitation. Finally, we report on the valuable experience acquired through in-situ commissioning of the system where simulated events were used to exercise the trigger chain. In particular we show critical quantities such as event processing times, measured in a large-scale HLT farm using a complex trigger menu

  3. Does heavy physical exertion trigger myocardial infarction?

    DEFF Research Database (Denmark)

    Hallqvist, J; Möller, J; Ahlbom, A

    2000-01-01

    To study possible triggering of first events of acute myocardial infarction by heavy physical exertion, the authors conducted a case-crossover analysis (1993-1994) within a population-based case-referent study in Stockholm County, Sweden (the Stockholm Heart Epidemiology Program). Interviews were...... million person-hours, and the attributable proportion was 5.7 percent. The risk was modified by physical fitness, with an increased risk being seen among sedentary subjects as in earlier studies, but the data also suggested a U-shaped association. In addition, the trigger effect was modified...

  4. Event reconstruction algorithms for the ATLAS trigger

    CERN Document Server

    Fonseca-Martin, T; Adragna, P; Aleksandrov, E; Aleksandrov, I; Amorim, A; Anderson, K; Anduaga, X; Aracena, I; Asquith, L; Avolio, G; Backlund, S; Badescu, E; Baines, J; Barria, P; Bartoldus, R; Batreanu, S; Beck, H P; Bee, C; Bell, P; Bell, W H; Bellomo, M; Benslama, K; Berge, D; Berger, N; Berry, T; Biglietti, M; Blair, R R; Bogaerts, A; Bold, T; Bosman, M; Boyd, J; Brelier, B; Burckhart-Chromek, D; Buttar, C; Campanelli, M; Caprini, M; Carlino, G; Casadei, D; Casado, M P; Cataldi, G; Cimino, D; Ciobotaru, M; Clements, D; Coccaro, A; Conde-Muíño, P; Conventi, F; Corso-Radu, A; Costa, M J; Coura Torres, R; Cranfeld, R; Cranmer, K; Crone, G; Dam, M; Damazio, D; Dawson, I; Dawson, J; De Almeida Simoes, J; De Cecco, S; De Santo, A; DellaPietra, M; Delsart, P A; Demers, S; Demirkoz, B; Di Mattia, A; Dionisi, C; Djilkibaev, R; Dobinson, R; Dobson, M; Dotti, A; Dova, M; Drake, G; Dufour, M A; Eckweiler, S; Ehrenfeld, W; Eifert, T; Ellis, Nick; Emeliyanov, D; Enoque Ferreira de Lima, D; Ermoline, Y; Eschrich, I; Facius, K; Falciano, S; Farthouat, P; Feng, E; Ferland, J; Ferrari, R; Ferrer, M L; Fischer, G; Francis, D; Gadomski, S; Garitaonandia Elejabarrieta, H; Gaudio, G; Gaumer, O; George, S; Giagu, S; Goncalo, R; Gorini, B; Gorini, E; Gowdy, S; Grabowska-Bold, I; Grancagnolo, S; Green, B; Haas, S; Haberichter, W; Hadavand, H; Haeberli, C; Haller, J; Hamilton, A; Hansen, J R; Hauschild, M; Hauser, R; Head, S; Hillier, S J; Höcker, A; Hrynóva, T; Hughes-Jones, R; Huston, J; Idarraga, J; Igonkina, O; Inada, M; Jain, V; Johns, K; Joos, M; Kama, S; Kanaya, N; Kazarov, A; Kehoe, R; Khoriauli, G; Kieft, G; Kilvington, G; Kirk, J; Kiyamura, H; Kolos, S; Kono, T; Konstantinidis, N; Korcyl, K; Kordas, K; Kotov, V; Krasznahorkay, A; Kubota, T; Kugel, A; Kuhn, D; Kurasige, H; Kuwabara, T; Kwee, R; Lankford, A; LeCompte, T; Leahu, L; Leahu, M; Ledroit, F; Lehmann-Miotto, G; Lei, X; Lellouch, D; Leyton, M; Li, S; Lim, H; Lohse, T; Losada, M; Luci, C; Luminari, L; Mapelli, L; Martin, B; Martin, B T; Marzano, F; Masik, J; McMahon, T; McPherson, R; Medinnis, M; Meessen, C; Meirosu, C; Messina, A; Mincer, A; Mineev, M; Misiejuk, A; Mönig, K; Monticelli, F; Moraes, A; Moreno, D; Morettini, P; Murillo Garcia, R; Nagano, K; Nagasaka, Y; Negri, A; Némethy, P; Neusiedl, A; Nisati, A; Nozicka, M; Omachi, C; Osculati, B; Osuna, C; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pauly, T; Perera, V; Pérez, E; Pérez-Réale, V; Petersen, J; Piegaia, R; Pilcher, J E; Pinzon, G; Pope, B; Potter, C; Primavera, M; Radescu, V; Rajagopalan, S; Renkel, P; Rescigno, M; Rieke, S; Risler, C; Riu, I; Robertson, S; Roda, C; Rodríguez, D; Rogriquez, Y; Ryabov, Yu; Ryan, P; Salvatore, D; Santamarina, C; Santamarina-Rios, C; Scannicchio, D; Scannicchio, D A; Schiavi, C; Schlereth, J L; Scholtes, I; Schooltz, D; Scott, W; Segura, E; Shimbo, N; Sidoti, A; Siragusa, G; Sivoklokov, S; Sloper, J E; Smizanska, M; Soloviev, I; Soluk, R; Spagnolo, S; Spiwoks, R; Stancu, S; Steinberg, P; Stelzer, J; Stradling, A; Strom, David M; Strong, J; Su, D; Sushkov, S; Sutton, M; Szymocha, T; Tapprogge, S; Tarem, S; Tarem, Z; Teixeira-Dias, P; Tokoshuku, K; Torrence, E; Touchard, F; Tremblet, L; Tripiana, M; Usai, G; Vachon, B; Vandelli, W; Ventura, A; Vercesi, V; Vermeulen, J; Von Der Schmitt, J; Wang, M; Watson, A; Wengler, T; Werner, P; Wheeler-Ellis, S; Wickens, F; Wiedenmann, W; Wielers, M; Wilkens, H; Winklmeier, F; Woerling, E E; Wu, S L; Wu, X; Xella, S; Yamazaki, Y; Yu, M; Zema, F; Zhang, J; Zhao, L; Zobernig, H; Dos Anjos, A; Zur Nedden, M; Ozcan, E; Ünel, G

    2008-01-01

    The ATLAS experiment under construction at CERN is due to begin operation at the end of 2007. The detector will record the results of proton-proton collisions at a center-of-mass energy of 14 TeV. The trigger is a three-tier system designed to identify in real-time potentially interesting events that are then saved for detailed offline analysis. The trigger system will select approximately 200 Hz of potentially interesting events out of the 40 MHz bunch-crossing rate (with 109 interactions per second at the nominal luminosity).

  5. Run 2 ATLAS Trigger and Detector Performance

    CERN Document Server

    Solovyanov, Oleg; The ATLAS collaboration

    2018-01-01

    The 2nd LHC run has started in June 2015 with a proton-proton centre-of-mass collision energy of 13 TeV. During the years 2016 and 2017, LHC delivered an unprecedented amount of luminosity under the ever-increasing challenging conditions in terms of peak luminosity, pile-up and trigger rates. In this talk, the LHC running conditions and the improvements made to the ATLAS experiment in the course of Run 2 will be discussed, and the latest ATLAS detector and ATLAS trigger performance results from the Run 2 will be presented.

  6. Hardware trigger processor for the MDT system

    CERN Document Server

    AUTHOR|(SzGeCERN)757787; The ATLAS collaboration; Hazen, Eric; Butler, John; Black, Kevin; Gastler, Daniel Edward; Ntekas, Konstantinos; Taffard, Anyes; Martinez Outschoorn, Verena; Ishino, Masaya; Okumura, Yasuyuki

    2017-01-01

    We are developing a low-latency hardware trigger processor for the Monitored Drift Tube system in the Muon spectrometer. The processor will fit candidate Muon tracks in the drift tubes in real time, improving significantly the momentum resolution provided by the dedicated trigger chambers. We present a novel pure-FPGA implementation of a Legendre transform segment finder, an associative-memory alternative implementation, an ARM (Zynq) processor-based track fitter, and compact ATCA carrier board architecture. The ATCA architecture is designed to allow a modular, staged approach to deployment of the system and exploration of alternative technologies.

  7. The vertex detector trigger data model

    CERN Document Server

    Koratzinos, M

    1998-01-01

    The aim of this note is to discuss the various issues arising from Different choices in the design of the Vertex Trigger Data Model and define a Baseline model. The pros and cons of the different choices will be presented with A recommendation of which choice constitutes the baseline solution and with a suggestion of the work plan to arrive to the final solution. This note does not try and define the definite version of the data model. However it is important to have a first version at this stage of the Vertex Trigger project.

  8. Iatrogenic urological triggers of autonomic dysreflexia

    DEFF Research Database (Denmark)

    Liu, N; Zhou, M; Biering-Sørensen, F

    2015-01-01

    dyssynergia. Without anesthesia, the majority of individuals develop AD during cystoscopy, transurethral litholapaxy and ESWL. The effectiveness of different anesthesia methods relies on blocking the nociceptive signals from the lower urinary tract (LUT) below the level of the neurological lesion. Other...... iatrogenic urological triggers were commonly associated with bladder filling. CONCLUSION: The LUT triggers of episodes of AD are often associated with iatrogenic urological procedures. AD was more prevalent in cervical SCI than in thoracic SCI. To detect this potential life-threatening complication following...

  9. Popular sweetner sucralose as a migraine trigger.

    Science.gov (United States)

    Patel, Rajendrakumar M; Sarma, Rakesh; Grimsley, Edwin

    2006-09-01

    Sucralose (trichlorogalactosucrose, or better known as Splenda) is an artificial sweetener from native sucrose that was approved by the FDA on April 1, 1998 (April Fool's Day). This observation of a potential causal relationship between sucralose and migraines may be important for physicians to remember this can be a possible trigger during dietary history taking. Identifying further triggers for migraine headaches, in this case sucralose, may help alleviate some of the cost burden (through expensive medical therapy or missed work opportunity) as well as provide relief to migraineurs.

  10. Optical and EUV studies of laser triggered Z-pinch discharges

    OpenAIRE

    Tobin, Isaac

    2014-01-01

    This thesis describes the results of experiments with two geometries of laser assisted discharge plasma. Both devices are designed for fast Z-pinch discharge, triggered by laser produced plasma generated by ablation of one or both electrodes. The laser plasma parameters are adjusted to control the plasma load while the discharge parameters are adjusted to yield a rate of rise of current greater than 1010 A/s. The expansion dynamics and emission characteristics of the plasma were analysed, wit...

  11. Efficient generation of cavitation bubbles and reactive oxygen species using triggered high-intensity focused ultrasound sequence for sonodynamic treatment

    Science.gov (United States)

    Yasuda, Jun; Yoshizawa, Shin; Umemura, Shin-ichiro

    2016-07-01

    Sonodynamic treatment is a method of treating cancer using reactive oxygen species (ROS) generated by cavitation bubbles in collaboration with a sonosensitizer at a target tissue. In this treatment method, both localized ROS generation and ROS generation with high efficiency are important. In this study, a triggered high-intensity focused ultrasound (HIFU) sequence, which consists of a short, extremely high intensity pulse immediately followed by a long, moderate-intensity burst, was employed for the efficient generation of ROS. In experiments, a solution sealed in a chamber was exposed to a triggered HIFU sequence. Then, the distribution of generated ROS was observed by the luminol reaction, and the amount of generated ROS was quantified using KI method. As a result, the localized ROS generation was demonstrated by light emission from the luminol reaction. Moreover, it was demonstrated that the triggered HIFU sequence has higher efficiency of ROS generation by both the KI method and the luminol reaction emission.

  12. UA1 upgrade first-level calorimeter trigger processor

    International Nuclear Information System (INIS)

    Bains, N.; Charlton, D.; Ellis, N.; Garvey, J.; Gregory, J.; Jimack, M.P.; Jovanovic, P.; Kenyon, I.R.; Baird, S.A.; Campbell, D.; Cawthraw, M.; Coughlan, J.; Flynn, P.; Galagedera, S.; Grayer, G.; Halsall, R.; Shah, T.P.; Stephens, R.; Eisenhandler, E.; Fensome, I.; Landon, M.

    1989-01-01

    A new first-level trigger processor has been built for the UA1 experiment on the Cern SppS Collider. The processor exploits the fine granularity of the new UA1 uranium-TMP calorimeter to improve the selectivity of the trigger. The new electron trigger has improved hadron jet rejection, achieved by requiring low energy deposition around the electromagnetic cluster. A missing transverse energy trigger and a total energy trigger have also been implemented. (orig.)

  13. Entity models for trigger-reaction documents

    NARCIS (Netherlands)

    Khalid, M.A.; Marx, M.; Makkes, M.X.

    2008-01-01

    We define the notion of an entity model for a special kind of document popular on the web: an article followed by a list of reactions on that article, usually by many authors, usually inverse chronologically ordered. We call these documents trigger-reactions pairs. The entity model describes which

  14. Trigger factors and mechanisms in migraine

    NARCIS (Netherlands)

    Schoonman, Geurt Gerhard

    2008-01-01

    Migraine is a severe headache syndrome, affecting approximately 33% of females and 13% of males. Patients suffer from recurring headache episodes in combination with nausea, vomiting, phono and photophobia. It is a paroxysmal disorder for which several several trigger factors have been identified by

  15. Triggered tremor sweet spots in Alaska

    Science.gov (United States)

    Gomberg, Joan; Prejean, Stephanie

    2013-01-01

    To better understand what controls fault slip along plate boundaries, we have exploited the abundance of seismic and geodetic data available from the richly varied tectonic environments composing Alaska. A search for tremor triggered by 11 large earthquakes throughout all of seismically monitored Alaska reveals two tremor “sweet spots”—regions where large-amplitude seismic waves repeatedly triggered tremor between 2006 and 2012. The two sweet spots locate in very different tectonic environments—one just trenchward and between the Aleutian islands of Unalaska and Akutan and the other in central mainland Alaska. The Unalaska/Akutan spot corroborates previous evidence that the region is ripe for tremor, perhaps because it is located where plate-interface frictional properties transition between stick-slip and stably sliding in both the dip direction and laterally. The mainland sweet spot coincides with a region of complex and uncertain plate interactions, and where no slow slip events or major crustal faults have been noted previously. Analyses showed that larger triggering wave amplitudes, and perhaps lower frequencies (sweet spots also does not occur during slow slip events visually detectable in GPS data, although slow slip below the detection threshold may have facilitated tremor triggering.

  16. Veto Studies for LIGO Inspiral Triggers

    OpenAIRE

    Christensen, Nelson

    2005-01-01

    LIGO recently conducted its third scientific data run, S3. Here we summarize the veto and data quality studies conducted by the LIGO Scientific Collaboration in connection with the search for binary inspiral signals in the S3 data. LIGO's interferometer channels and physical environmental monitors were monitored, and events in these channels coincident with inspiral triggers were examined.

  17. Method for breathing related ECG triggering

    Energy Technology Data Exchange (ETDEWEB)

    Waters, W.; Neeb, W.; Wellner, U.

    1984-02-01

    A method for breathing related ECG triggering has been developed. It can be applied in radionuclid-angiocardioscintigraphy promising new insights into the physiology and pathophysiology of breathing related heart function without invasive manipulations. High resolution images of the heart can be obtained using this method by steering the NMR (nuclear magnetic resonance) or the cine CT (ultrafast transmission computerized tomography) acquisition.

  18. The CMS Barrel Muon Trigger Upgrade

    CERN Document Server

    Triossi, Andrea

    2017-01-01

    ABSTRACT: The increase of luminosity expected by LHC during Phase 1 will impose several constrains for rate reduction while maintaining high efficiency in the CMS Level 1 trigger system. The TwinMux system is the early layer of the muon barrel region that concentrates the information from different subdetectors DT, RPC and HO. It arranges and fan-out the slow optical trigger links from the detector chambers into faster links (10 Gbps) that are sent to the track finders. Results, from collision runs, that confirm the satisfactory operation of the trigger system up to the output of the barrel track finder, will be shown. SUMMARY: In view of the increase of luminosity during phase 1 upgrade of LHC, the muon trigger chain of the Compact Muon Solenoid (CMS) experiment underwent considerable improvements. The muon detector was designed for preserving the complementarity and redundancy of three separate muon detection systems, Cathode Strip Chambers (CSC), Drift Tubes (DT) and Resistive Plate Chambers (RPC), until ...

  19. BTeV trigger/DAQ innovations

    International Nuclear Information System (INIS)

    Votava, Margaret

    2005-01-01

    The BTeV experiment was a collider based high energy physics (HEP) B-physics experiment proposed at Fermilab. It included a large-scale, high speed trigger/data acquisition (DAQ) system, reading data off the detector at 500 Gbytes/sec and writing to mass storage at 200 Mbytes/sec. The online design was considered to be highly credible in terms of technical feasibility, schedule and cost. This paper will give an overview of the overall trigger/DAQ architecture, highlight some of the challenges, and describe the BTeV approach to solving some of the technical challenges. At the time of termination in early 2005, the experiment had just passed its baseline review. Although not fully implemented, many of the architecture choices, design, and prototype work for the online system (both trigger and DAQ) were well on their way to completion. Other large, high-speed online systems may have interest in the some of the design choices and directions of BTeV, including (a) a commodity-based tracking trigger running asynchronously at full rate, (b) the hierarchical control and fault tolerance in a large real time environment, (c) a partitioning model that supports offline processing on the online farms during idle periods with plans for dynamic load balancing, and (d) an independent parallel highway architecture

  20. Mechanisms and environmental signals triggering frost hardening ...

    Indian Academy of Sciences (India)

    2004-10-28

    Oct 28, 2004 ... Home; Journals; Journal of Biosciences; Volume 29; Issue 4. Plant resistance to cold stress: Mechanisms and environmental signals triggering frost hardening and dehardening ... Keywords. Cold acclimation of plants; environmental signals; frost hardening; photoperiod; phytochrome; Scots pine ...

  1. Triggering on electrons and photons with CMS

    Directory of Open Access Journals (Sweden)

    Zabi Alexandre

    2012-06-01

    Full Text Available Throughout the year 2011, the Large Hadron Collider (LHC has operated with an instantaneous luminosity that has risen continually to around 4 × 1033cm−2s−1. With this prodigious high-energy proton collisions rate, efficient triggering on electrons and photons has become a major challenge for the LHC experiments. The Compact Muon Solenoid (CMS experiment implements a sophisticated two-level online selection system that achieves a rejection factor of nearly 106. The first level (L1 is based on coarse information coming from the calorimeters and the muon detectors while the High-Level Trigger (HLT combines fine-grain information from all sub-detectors. In this intense hadronic environment, the L1 electron/photon trigger provides a powerful tool to select interesting events. It is based upon information from the Electromagnetic Calorimeter (ECAL, a high-resolution detector comprising 75848 lead tungstate (PbWO4 crystals in a “barrel” and two “endcaps”. The performance as well as the optimization of the electron/photon trigger are presented.

  2. ALICE Trigger and Event Selection QA

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    I will present the last nine weeks of work on building a class that efficiently produces trending physics selection of various trigger classes for the purposes of quality assurance. This class is easily generalizable and will be used for live monitoring via a webpage.

  3. What Triggers Supramolecular Isomerism in Nonmolecular Solids ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 128; Issue 11. What Triggers ... interpret the phase diagram of a system. The structure-synthesis correlation discussed here provides chemical insight to evolve a synthetic protocol to interpret and predict the possibilityof supramolecular isomers in metal organic solids.

  4. Aircraft Detectors, Trap Triggers and Combination Locks

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 2. Aircraft Detectors, Trap Triggers and Combination Locks - Functional Diversity of Insect Mechanosensory Hairs. Jürgen Tautz. General Article Volume 5 Issue 2 February 2000 pp 32-38 ...

  5. An overview of the ATLAS trigger

    CERN Document Server

    Le Dû, P

    1999-01-01

    Summary form only given. This paper gives an overview of the event selection for ATLAS, prior to event building, with the emphasis on the level-2 trigger. (A further stage of selection after event building is described in a separate presentation-ref Event Filter overview.) The level-1 trigger based on custom hardware processes coarse-grain data from the calorimeters and dedicated muon trigger chambers to give a selection of approximately one interaction in 10**5 (one bunch crossing in 10**3). The level-2 trigger processes selected fine-grain data from all detectors to give a further selection of one in 10**2. Studies of the estimated physics rates and detector data volumes have led to a sequential level-2 selection strategy guided by Region of Interest pointers from level-1. The influence of low luminosity (b physics) and high luminosity (high pT) running on the strategy and the architectural options is discussed. The models and testbeds used in developing and testing the strategy are described. Finally the t...

  6. ATLAS LEVEL-1 CALORIMETER AND TOPOLOGICAL TRIGGER

    CERN Document Server

    Weber, Sebastian Mario; The ATLAS collaboration

    2017-01-01

    In Run 2 at CERN's Large Hadron Collider, the ATLAS detector uses a two-level trigger system to reduce the event rate from the nominal collision rate of 40 MHz to the event storage rate of 1 kHz, while preserving interesting physics events. The first step of the trigger system, Level-1, reduces the event rate to 100 kHz with a latency of less than 2.5 μs. One component of this system is the Level-1 Calorimeter Trigger (L1Calo), which uses coarse-granularity information from the electromagnetic and hadronic calorimeters to identify regions of interest corresponding to electrons, photons, taus, jets, and large amounts of transverse energy and missing transverse energy. In this talk, we will discuss the improved performance of the L1Calo system in the challenging, high-luminosity conditions provided by the LHC in Run 2. As the LHC exceeds its design luminosity, it is becoming even more critical to reduce event rates while preserving physics. A new feature of the ATLAS Run 2 trigger system is the Level-1 Topolog...

  7. Self-triggered coordination with ternary controllers

    NARCIS (Netherlands)

    De Persis, Claudio; Frasca, Paolo

    2012-01-01

    This paper regards coordination of networked systems with ternary controllers. We develop a hybrid coordination system which implements a self-triggered communication policy, based on polling the neighbors upon need. We prove that the proposed scheme ensures finite-time convergence to a neighborhood

  8. Reflex epilepsy: triggers and management strategies

    Directory of Open Access Journals (Sweden)

    Okudan ZV

    2018-01-01

    Full Text Available Zeynep Vildan Okudan,1 Çiğdem Özkara2 1Department of Neurology, Bakirkoy Dr Sadi Konuk Education and Research Hospital, 2Department of Neurology and Clinical Neurophysiology, Cerrahpasa Faculty of Medicine, University of Istanbul, Istanbul, Turkey Abstract: Reflex epilepsies (REs are identified as epileptic seizures that are consistently induced by identifiable and objective-specific triggers, which may be an afferent stimulus or by the patient’s own activity. RE may have different subtypes depending on the stimulus characteristic. There are significant clinical and electrophysiologic differences between different RE types. Visual stimuli-sensitive or photosensitive epilepsies constitute a large proportion of the RE and are mainly related to genetic causes. Reflex epilepsies may present with focal or generalized seizures due to specific triggers, and sometimes seizures may occur spontaneously. The stimuli can be external (light flashes, hot water, internal (emotion, thinking, or both and should be distinguished from triggering precipitants, which most epileptic patients could report such as emotional stress, sleep deprivation, alcohol, and menstrual cycle. Different genetic and acquired factors may play a role in etiology of RE. This review will provide a current overview of the triggering factors and management of reflex seizures. Keywords: seizure, reflex epilepsy, photosensitivity, hot water, reading, thinking

  9. Irrelevant Words Trigger an Attentional Blink

    NARCIS (Netherlands)

    Stein, T.; Zwickel, J.; Kitzmantel, M.; Ritter, J.; Schneider, W.X.

    2010-01-01

    It has been argued that salient distractor items displayed during rapid serial visual presentation (RSVP) trigger an attentional blink (AB) when they share features with the target item. Here we demonstrate that salient distractor words induce an AB independently of feature overlap with the target.

  10. Prostate cancer may trigger paraneoplastic limbic encephalitis

    DEFF Research Database (Denmark)

    Jakobsen, Jakob Kristian; Zakharia, Elias Raja; Boysen, Anders Kindberg

    2012-01-01

    -Hu antibody test the patient was diagnosed with paraneoplastic limbic encephalitis related to prostate cancer. The patient died within 6 months. We review the literature on prostate cancer-related paraneoplastic limbic encephalitis. High-risk prostate cancer can trigger paraneoplastic limbic encephalitis...

  11. Event Reconstruction Algorithms for the ATLAS Trigger

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca-Martin, T.; /CERN; Abolins, M.; /Michigan State U.; Adragna, P.; /Queen Mary, U. of London; Aleksandrov, E.; /Dubna, JINR; Aleksandrov, I.; /Dubna, JINR; Amorim, A.; /Lisbon, LIFEP; Anderson, K.; /Chicago U., EFI; Anduaga, X.; /La Plata U.; Aracena, I.; /SLAC; Asquith, L.; /University Coll. London; Avolio, G.; /CERN; Backlund, S.; /CERN; Badescu, E.; /Bucharest, IFIN-HH; Baines, J.; /Rutherford; Barria, P.; /Rome U. /INFN, Rome; Bartoldus, R.; /SLAC; Batreanu, S.; /Bucharest, IFIN-HH /CERN; Beck, H.P.; /Bern U.; Bee, C.; /Marseille, CPPM; Bell, P.; /Manchester U.; Bell, W.H.; /Glasgow U. /Pavia U. /INFN, Pavia /Regina U. /CERN /Annecy, LAPP /Paris, IN2P3 /Royal Holloway, U. of London /Napoli Seconda U. /INFN, Naples /Argonne /CERN /UC, Irvine /Barcelona, IFAE /Barcelona, Autonoma U. /CERN /Montreal U. /CERN /Glasgow U. /Michigan State U. /Bucharest, IFIN-HH /Napoli Seconda U. /INFN, Naples /New York U. /Barcelona, IFAE /Barcelona, Autonoma U. /Salento U. /INFN, Lecce /Pisa U. /INFN, Pisa /Bucharest, IFIN-HH /UC, Irvine /CERN /Glasgow U. /INFN, Genoa /Genoa U. /Lisbon, LIFEP /Napoli Seconda U. /INFN, Naples /UC, Irvine /Valencia U. /Rio de Janeiro Federal U. /University Coll. London /New York U.; /more authors..

    2011-11-09

    The ATLAS experiment under construction at CERN is due to begin operation at the end of 2007. The detector will record the results of proton-proton collisions at a center-of-mass energy of 14 TeV. The trigger is a three-tier system designed to identify in real-time potentially interesting events that are then saved for detailed offline analysis. The trigger system will select approximately 200 Hz of potentially interesting events out of the 40 MHz bunch-crossing rate (with 10{sup 9} interactions per second at the nominal luminosity). Algorithms used in the trigger system to identify different event features of interest will be described, as well as their expected performance in terms of selection efficiency, background rejection and computation time per event. The talk will concentrate on recent improvements and on performance studies, using a very detailed simulation of the ATLAS detector and electronics chain that emulates the raw data as it will appear at the input to the trigger system.

  12. Triggered star formation and its consequences

    Science.gov (United States)

    Li, Shule; Frank, Adam; Blackman, Eric G.

    2014-11-01

    Star formation can be triggered by compression from wind or supernova-driven shock waves that sweep over molecular clouds. Because these shocks will likely contain processed elements, triggered star formation has been proposed as an explanation for short-lived radioactive isotopes (SLRIs) in the Solar system. Previous studies have tracked the triggering event to the earliest phases of collapse and have focused on the shock properties required for both successful star formation and mixing of SLRIs. In this paper, we use adaptive mesh refinement simulation methods, including sink particles, to simulate the full collapse and subsequent evolution of a stable Bonnor- Ebert sphere subjected to a shock and post-shock wind. We track the flow of the cloud material after a star (a sink particle) has formed. For non-rotating clouds, we find robust triggered collapse and little bound circumstellar material remaining around the post-shock collapsed core. When we add initial cloud rotation, we observe the formation of discs around the collapsed core which then interact with the post-shock flow. Our results indicate that these circumstellar discs are massive enough to form planets and are long lived, in spite of the ablation driven by post-shock-flow ram pressure. As a function of the initial conditions, we also track the time evolution of the accretion rates and particle mixing between the ambient wind and cloud material. The latter is maximized for cases of highest Mach number.

  13. Is stress a trigger factor for migraine?

    NARCIS (Netherlands)

    Schoonman, G.G.; Evers, D.J.; Ballieux, B.E.; de Geus, E.J.C.; de Kloet, E.R.; Terwindt, G.M.; van Dijk, J.G.; Ferrari, M.D.

    2007-01-01

    Background: Although mental stress is commonly considered to be an important trigger factor for migraine, experimental evidence for this belief is yet lacking. Objective: To study the temporal relationship between changes in stress-related parameters (both subjective and objective) and the onset of

  14. Event reconstruction algorithms for the ATLAS trigger

    International Nuclear Information System (INIS)

    F-Martin, T; Avolio, G; Backlund, S; Abolins, M; Adragna, P; Aleksandrov, E; Aleksandrov, I; Amorim, A; Anderson, K; Anduaga, X; Aracena, I; Bartoldus, R; Asquith, L; Badescu, E; Baines, J; Beck, H P; Bee, C; Bell, P; Barria, P; Batreanu, S

    2008-01-01

    The ATLAS experiment under construction at CERN is due to begin operation at the end of 2007. The detector will record the results of proton-proton collisions at a center-of-mass energy of 14 TeV. The trigger is a three-tier system designed to identify in real-time potentially interesting events that are then saved for detailed offline analysis. The trigger system will select approximately 200 Hz of potentially interesting events out of the 40 MHz bunch-crossing rate (with 10 9 interactions per second at the nominal luminosity). Algorithms used in the trigger system to identify different event features of interest will be described, as well as their expected performance in terms of selection efficiency, background rejection and computation time per event. The talk will concentrate on recent improvements and on performance studies, using a very detailed simulation of the ATLAS detector and electronics chain that emulates the raw data as it will appear at the input to the trigger system

  15. Level 1 Tau trigger performance in 2016 data and VBF seeds at Level 1 trigger

    CERN Document Server

    CMS Collaboration

    2017-01-01

    After the first long shutdown, the LHC has restarted at a centre-of-mass energy of 13 TeV. In 2016, the LHC achieved an instantaneous luminosity larger than $10^{34}$ $\\mathrm{cm}^{-2}\\cdot \\mathrm{s}^{-1}$ and a peak average pile-up of more than 40. The CMS Level-1 trigger architecture has undergone a full upgrade in order to maintain and improve the trigger performance under these new conditions. It allows CMS to keep the trigger rate under control and to avoid a significant increase in trigger thresholds that would have a negative impact on the CMS physics program. Studies of the performance of the calorimeter trigger upgrade for tau leptons, using the full 2016 dataset (35.9 $\\mathrm{fb}^{-1}$), are shown. Details of the Level-1 trigger algorithms and commissioning may be found in CMS-DP-2015-009, CMS-DP-2015-003, CMS-DP-2015-051 and the CMS Technical Design Report for the Level-1 Trigger upgrade: CERN-LHCC-2013-011, CMS-TDR-12 (2013). Previous performance results, based on the ICHEP 2016 dataset (12.9 ...

  16. CLUSTER FORMATION TRIGGERED BY FILAMENT COLLISIONS IN SERPENS SOUTH

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Fumitaka; Kawabe, Ryohei; Shinnaga, Hiroko [National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Sugitani, Koji [Graduate School of Natural Sciences, Nagoya City University, Mizuho-ku, Nagoya 467-8501 (Japan); Tanaka, Tomohiro; Kimura, Kimihiko; Tokuda, Kazuki; Kozu, Minato; Okada, Nozomi; Hasegawa, Yutaka; Ogawa, Hideo [Department of Physical Science, Osaka Prefecture University, Gakuen 1-1, Sakai, Osaka 599-8531 (Japan); Nishitani, Hiroyuki; Mizuno, Izumi [Nobeyama Radio Observatory, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Dobashi, Kazuhito; Shimoikura, Tomomi [Department of Astronomy and Earth Sciences, Tokyo Gakugei University, Koganei, Tokyo 184-8501 (Japan); Shimajiri, Yoshito [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot, IRFU/Service d' Astrophysique, CEA Saclay, F-91191 Gif-sur-Yvette (France); Yonekura, Yoshinori [Center for Astronomy, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512 (Japan); Kameno, Seiji [Joint ALMA Observatory, Alonso de Crdova 3107 Vitacura, Santiago (Chile); Momose, Munetake [Institute of Astrophysics and Planetary Sciences, Ibaraki University, Bunkyo 2-1-1, Mito 310-8512 (Japan); Nakajima, Taku, E-mail: fumitaka.nakamura@nao.ac.jp [Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan); and others

    2014-08-20

    The Serpens South infrared dark cloud consists of several filamentary ridges, some of which fragment into dense clumps. On the basis of CCS (J{sub N} = 4{sub 3}-3{sub 2}), HC{sub 3}N (J = 5-4), N{sub 2}H{sup +} (J = 1-0), and SiO (J = 2-1, v = 0) observations, we investigated the kinematics and chemical evolution of these filamentary ridges. We find that CCS is extremely abundant along the main filament in the protocluster clump. We emphasize that Serpens South is the first cluster-forming region where extremely strong CCS emission is detected. The CCS-to-N{sub 2}H{sup +} abundance ratio is estimated to be about 0.5 toward the protocluster clump, whereas it is about 3 in the other parts of the main filament. We identify six dense ridges with different V {sub LSR}. These ridges appear to converge toward the protocluster clump, suggesting that the collisions of these ridges may have triggered cluster formation. The collisions presumably happened within a few × 10{sup 5} yr because CCS is abundant only for a short time. The short lifetime agrees with the fact that the number fraction of Class I objects, whose typical lifetime is 0.4 × 10{sup 5} yr, is extremely high, about 70% in the protocluster clump. In the northern part, two ridges appear to have partially collided, forming a V-shape clump. In addition, we detected strong bipolar SiO emission that is due to the molecular outflow blowing out of the protostellar clump, as well as extended weak SiO emission that may originate from the filament collisions.

  17. Production of Loop-Top Hard X-Ray Emission

    Science.gov (United States)

    Miller, James A.; Seaquist, Valerie

    2003-01-01

    The main goal of this work has been to understand the particle acceleration mechanism (or mechanisms) in impulsive solar flares, using hard X-ray observations of high spatial and spectral resolution. Several new observations, including the observations by YOHKOH that reveal emission from both footpoints and loop tops, have suggested to us that a model employing stochastic acceleration is the most likely candidate for explaining energetic particles in a majority (if not all) of impulsive flares. In this model, most of the flare energy is initially converted into plasma waves and turbulence, which in turn can accelerate particles from thermal to relativistic energies on sub-second timescales. This research has provided important tools for the interpretation of the high spectral and spatial resolution observations obtained from the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) . In the course of our research, we have focused on two different (but possibly related) stochastic acceleration models: (1) a model that employs high-frequency whistler turbulence and concentrates on the energetic electrons, and (2) a model that employs low frequency MHD waves, and is able to accelerate both the ambient electrons and ions.

  18. Acoustic emission

    International Nuclear Information System (INIS)

    Straus, A.; Lopez Pumarega, M.I.; Di Gaetano, J.O.; D'Atellis, C.E.; Ruzzante, J.E.

    1990-01-01

    This paper is related to our activities on acoustic emission (A.E.). The work is made with different materials: metals and fibre reinforced plastics. At present, acoustic emission transducers are being developed for low and high temperature. A test to detect electrical discharges in electrical transformers was performed. Our experience in industrial tests to detect cracks or failures in tanks or tubes is also described. The use of A.E. for leak detection is considered. Works on pattern recognition of A.E. signals are also being performed. (Author)

  19. Experimental Study on Triggering Characteristics of a Surface Flashover Triggered Vacuum Switch

    International Nuclear Information System (INIS)

    Yao Xueling; Chen Jingliang; Sun Wei

    2010-01-01

    Triggering characteristics of triggered vacuum switch (TVS), including the discharge delay time, delay jitter, range of operational voltage and peak of pulsed current, are investigated. Both structure and experimental circuit of TVS are presented. The results indicate that TVS, as a surface flashover triggering device with high dielectric permittivity material, is with excellent triggering characteristics. When the hold-off voltage reaches 120 kV, the minimum operational voltage is 1.3 kV, and the minimum discharge delay time and jitter are 100 ns and ±10 ns, respectively. The peak current is up to 240 kA when the operational voltage reaches 100 kV. TVS can well satisfy the main demands of high voltage and current applications, and can also be used under a multi-crowbar circuit.

  20. The ATLAS online High Level Trigger framework experience reusing offline software components in the ATLAS trigger

    CERN Document Server

    Wiedenmann, W

    2009-01-01

    Event selection in the Atlas High Level Trigger is accomplished to a large extent by reusing software components and event selection algorithms developed and tested in an offline environment. Many of these offline software modules are not specifically designed to run in a heavily multi-threaded online data flow environment. The Atlas High Level Trigger (HLT) framework based on the Gaudi and Atlas Athena frameworks, forms the interface layer, which allows the execution of the HLT selection and monitoring code within the online run control and data flow software. While such an approach provides a unified environment for trigger event selection across all of Atlas, it also poses strict requirements on the reused software components in terms of performance, memory usage and stability. Experience of running the HLT selection software in the different environments and especially on large multi-node trigger farms has been gained in several commissioning periods using preloaded Monte Carlo events, in data taking peri...

  1. Pattern-triggered immunity suppresses programmed cell death triggered by fumonisin b1.

    Directory of Open Access Journals (Sweden)

    Daisuke Igarashi

    Full Text Available Programmed cell death (PCD is a crucial process for plant innate immunity and development. In plant innate immunity, PCD is believed to prevent the spread of pathogens from the infection site. Although proper control of PCD is important for plant fitness, we have limited understanding of the molecular mechanisms regulating plant PCD. Plant innate immunity triggered by recognition of effectors (effector-triggered immunity, ETI is often associated with PCD. However pattern-triggered immunity (PTI, which is triggered by recognition of elicitors called microbe-associated molecular patterns (MAMPs, is not. Therefore we hypothesized that PTI might suppress PCD. Here we report that PCD triggered by the mycotoxin fumonisin B1 (FB1 can be suppressed by PTI in Arabidopsis. FB1-triggered cell death was suppressed by treatment with the MAMPs flg22 (a part of bacterial flagellin or elf18 (a part of the bacterial elongation factor EF-Tu but not chitin (a component of fungal cell walls. Although plant hormone signaling is associated with PCD and PTI, both FB1-triggered cell death and suppression of cell death by flg22 treatment were still observed in mutants deficient in jasmonic acid (JA, ethylene (ET and salicylic acid (SA signaling. The MAP kinases MPK3 and MPK6 are transiently activated and inactivated within one hour during PTI. We found that FB1 activated MPK3 and MPK6 about 36-48 hours after treatment. Interestingly, this late activation was attenuated by flg22 treatment. These results suggest that PTI suppression of FB1-triggered cell death may involve suppression of MPK3/MPK6 signaling but does not require JA/ET/SA signaling.

  2. The ATLAS High Level Trigger Steering Framework and the Trigger 
Configuration System.

    CERN Document Server

    Pérez Cavalcanti, Tiago; The ATLAS collaboration

    2011-01-01

    The ATLAS High Level Trigger Steering Framework and the Trigger 
Configuration System.
 
The ATLAS detector system installed in the Large Hadron Collider (LHC) 
at CERN is designed to study proton-proton and nucleus-nucleus 
collisions with a maximum center of mass energy of 14 TeV at a bunch 
collision rate of 40MHz.  In March 2010 the four LHC experiments saw 
the first proton-proton collisions at 7 TeV. Still within the year a 
collision rate of nearly 10 MHz is expected. At ATLAS, events of 
potential interest for ATLAS physics are selected by a three-level 
trigger system, with a final recording rate of about 200 Hz. The first 
level (L1) is implemented in custom hardware; the two levels of 
the high level trigger (HLT) are software triggers, running on large 
farms of standard computers and network devices. 

Within the ATLAS physics program more than 500 trigger signatures are 
defined. The HLT tests each signature on each L1-accepted event; the 
test outcome is recor...

  3. Performance of muon-based triggers at the CMS High Level Trigger

    CERN Document Server

    Alimena, Juliette

    2014-01-01

    The trigger systems of the CERN LHC detectors play a crucial role in determining the physics capabilities of the experiments. A reduction of several orders of magnitude of the event rate is needed to reach values compatible with the detector readout, offline storage and analysis capabilities. The CMS experiment has been designed with a two-level trigger system: the Level 1 (L1) Trigger, implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS reconstruction and analysis software running on a computer farm. Here we will present the design and performance of the main muon triggers used during the Run I data taking. We will show how these triggers contributed to the 2012 physics results. We will then present the improvements foreseen to meet the challenges of the Run II data taking. We will discuss the improvements being made at L1, and at various stages in the HLT reconstruction, ranging from the local drift tube and cathode strip chamber reconstruction, to ...

  4. Acoustic emission

    Indian Academy of Sciences (India)

    3Universidade do Minho, Department Engineering Mecânica, Azurém,. 4800058 Guimar˜aes, Portugal e-mail: mathew@dem.uminho.pt. Abstract. Acoustic Emission (AE) has been widely used for monitoring man- ufacturing processes particularly those involving metal cutting. Monitoring the condition of the cutting tool in the ...

  5. The CLEO-III Trigger: Decision and gating

    International Nuclear Information System (INIS)

    Bergfeld, T.J.; Gollin, G.D.; Haney, M.J.

    1996-01-01

    The CLEO-III Trigger provides a trigger decision every 42ns, with a latency of approximately 2.5μs. This paper describes the free-running, pipelined trigger decision logic, the throttling mechanism whereby the data acquisition system can modulate the trigger rate to maximize throughput without buffer overrun, and the subsequent signal distribution mechanism for delivering the trigger decision to the front-end electronics. This paper also describes the multilevel simulation methods employed to allow detailed low-level models of trigger components to be co-simulated with more abstract system models, thus allowing full system modeling without incurring prohibitive computational overheads

  6. Particle combinations in the LHCb Upgrade trigger

    CERN Document Server

    Zhao, Fanyi

    2017-01-01

    The LHCb experiment will be upgraded during long shutdown II (2018-2020) to process inelastic proton-proton collisions at 30MHz in a software application and run at a higher instantaneous luminosity of $2\\times 10^{33}cm^{−2}s^{−1}$. Each of these collisions will contain substantially more proton-proton interactions and charged particles. It is important to identify the decay vertices of heavy-flavour hadrons produced by the primary proton-proton interaction in an efficient, CPU-performant manner. In this project, I will learn about the LHCb trigger and experimental programme and investigate alternative models for reconstructing these vertices, which may scale more efficiently to the upgraded trigger conditions than the current model.

  7. Checkpoint triggering in a computer system

    Science.gov (United States)

    Cher, Chen-Yong

    2016-09-06

    According to an aspect, a method for triggering creation of a checkpoint in a computer system includes executing a task in a processing node of the computer system and determining whether it is time to read a monitor associated with a metric of the task. The monitor is read to determine a value of the metric based on determining that it is time to read the monitor. A threshold for triggering creation of the checkpoint is determined based on the value of the metric. Based on determining that the value of the metric has crossed the threshold, the checkpoint including state data of the task is created to enable restarting execution of the task upon a restart operation.

  8. The ATLAS Trigger Simulation with Legacy Software

    CERN Document Server

    Bernius, Catrin; The ATLAS collaboration

    2017-01-01

    Physics analyses at the LHC which search for rare physics processes or measure Standard Model parameters with high precision require accurate simulations of the detector response and the event selection processes. The accurate simulation of the trigger response is crucial for determination of overall selection efficiencies and signal sensitivities. For the generation and the reconstruction of simulated event data, generally the most recent software releases are used to ensure the best agreement between simulated data and real data. For the simulation of the trigger selection process, however, the same software release with which real data were taken should be ideally used. This requires potentially running with software dating many years back, the so-called legacy software. Therefore having a strategy for running legacy software in a modern environment becomes essential when data simulated for past years start to present a sizeable fraction of the total. The requirements and possibilities for such a simulatio...

  9. Machine learning techniques for razor triggers

    CERN Document Server

    Kolosova, Marina

    2015-01-01

    My project was focused on the development of a neural network which can predict if an event passes or not a razor trigger. Using synthetic data containing jets and missing transverse energy we built and trained a razor network by supervised learning. We accomplished a ∼ 91% agreement between the output of the neural network and the target while the other 10% was due to the noise of the neural network. We could apply such networks during the L1 trigger using neuromorhic hardware. Neuromorphic chips are electronic systems that function in a way similar to an actual brain, they are faster than GPUs or CPUs, but they can only be used with spiking neural networks.

  10. Conservative treatment for trigger thumb in children.

    Science.gov (United States)

    Watanabe, H; Hamada, Y; Toshima, T; Nagasawa, K

    2001-07-01

    Conservative treatment was performed for 60 trigger thumbs (19 right, 17 left, 12 bilateral) in 48 children (19 boys, 29 girls); the age at initial diagnosis ranged from 0 to 48 months old (mean 26 months). In this approach, only passive exercise of the affected thumb was performed by the mother. As a result, two patients (two thumbs) dropped out of treatment. Fifty-six thumbs out of 58 showed a satisfactory result (96%). Sixteen thumbs (in stage 2) and eight thumbs (in stage 3) showed completely recovery. Four thumbs (in stage 3) have not yet improved. In conclusion, we suggest that conservative treatment is effective for trigger thumbs in stage 2, while surgical therapy was thought to be indicated for stage 3 before the age of 3 years to avoid flexion deformity.

  11. RF gun using laser-triggered photocathode

    International Nuclear Information System (INIS)

    Akiyama, H.; Otake, Y.; Naito, T.; Takeuchi, Y.; Yoshioka, M.

    1992-01-01

    An RF gun using laser-triggered photocathode has many advantages as an injector of the linear colliders since it can generate a low emittance and high current pulsed beam. The experimental facility for the RF gun, such as an RF system, a laser system and a photocathode have been fabricated to study the fundamental characteristics. The dynamics of the RF gun has also studied by the 1D sheet beam model. (author)

  12. Triggering of Suicidal Erythrocyte Death by Gefitinib

    OpenAIRE

    Abdulla Al Mamun Bhuyan; Teresa Wagner; Hang Cao; Florian Lang

    2017-01-01

    Background/Aims: The epidermal growth factor receptor-tyrosine kinase inhibitor gefitinib is effective against several malignancies and is mainly utilized in the treatment of epidermal growth factor receptor mutation positive non-small cell lung cancer. The anti-cancer effect of the drug involves stimulation of apoptosis. Side effects of gefitinib include anemia. At least in theory, the development of anemia during gefitinib treatment could result from triggering of eryptosis, the suicidal er...

  13. Acoustic Manifestations of Natural versus Triggered Lightning

    Science.gov (United States)

    Arechiga, R. O.; Johnson, J. B.; Edens, H. E.; Rison, W.; Thomas, R. J.; Eack, K.; Eastvedt, E. M.; Aulich, G. D.; Trueblood, J.

    2010-12-01

    Positive leaders are rarely detected by VHF lightning detection systems; positive leader channels are usually outlined only by recoil events. Positive cloud-to-ground (CG) channels are usually not mapped. The goal of this work is to study the types of thunder produced by natural versus triggered lightning and to assess which types of thunder signals have electromagnetic activity detected by the lightning mapping array (LMA). Towards this end we are investigating the lightning detection capabilities of acoustic techniques, and comparing them with the LMA. In a previous study we used array beam forming and time of flight information to locate acoustic sources associated with lightning. Even though there was some mismatch, generally LMA and acoustic techniques saw the same phenomena. To increase the database of acoustic data from lightning, we deployed a network of three infrasound arrays (30 m aperture) during the summer of 2010 (August 3 to present) in the Magdalena mountains of New Mexico, to monitor infrasound (below 20 Hz) and audio range sources due to natural and triggered lightning. The arrays were located at a range of distances (60 to 1400 m) surrounding the triggering site, called the Kiva, used by Langmuir Laboratory to launch rockets. We have continuous acoustic measurements of lightning data from July 20 to September 18 of 2009, and from August 3 to September 1 of 2010. So far, lightning activity around the Kiva was higher during the summer of 2009. We will present acoustic data from several interesting lightning flashes including a comparison between a natural and a triggered one.

  14. Boredom and Passion: Triggers of Habitual Entrepreneurship

    DEFF Research Database (Denmark)

    Müller, Sabine; Neergaard, Helle

    To date, habitual entrepreneurship research has mainly focused on comparing novice with habitual business founders and creating typologies. The purpose of this paper is to examine and explain the underlying reasons why habitual entrepreneurs establish new businesses repeatedly and continually....... The case based, the study identifies eight factors, which contribute to consecutive venture creation. The findings suggest that boredom and passion are necessary conditions triggering habitual entrepreneurship. Other important mechanisms included the joy of discovering and exploiting an opportunity...

  15. Surgical Treatment of Trigger Finger: Open Release

    Directory of Open Access Journals (Sweden)

    Firat Ozan

    2016-01-01

    Full Text Available In this study, open A1 pulley release results were evaluated in patients with a trigger finger diagnosis. 45 patients (29 females, 16 males, mean age 50.7 ± 11.9; range (24-79, 45 trigger fingers were released via open surgical technique. On the 25 of 45 cases were involved in the right hand and 16 of them were at the thumb, 2 at index, 6 at the middle and 1 at ring finger. Similarly, at the left hand, 15 of 20 cases were at the thumb, 1 at the index finger, 2 at middle finger and 2 at ring finger. Average follow-up time was 10.2 ± 2.7 (range, 6-15 months. Comorbidities in patients were; diabetes mellitus at 6 cases (13.3%, hypertension at 11 cases (24.4%, hyperthyroidism at 2 cases (4.4%, dyslipidemia at 2 cases (4.4% and lastly 2 cases had carpal tunnel syndrome operation. The mean time between the onset of symptoms to surgery was 6.9 ± 4.8 (range, 2-24 months. Patient satisfaction was very good in 34 cases (75.4% and good in 11 (24.6% patients. The distance between the pulpa of the operated finger and the palm was normal in every case postoperatively. We have not encountered any postoperative complications. We can recommend that; A1 pulley release via open incision is an effective and reliable method in trigger finger surgery.

  16. CMS High Level Trigger Timing Measurements

    International Nuclear Information System (INIS)

    Richardson, Clint

    2015-01-01

    The two-level trigger system employed by CMS consists of the Level 1 (L1) Trigger, which is implemented using custom-built electronics, and the High Level Trigger (HLT), a farm of commercial CPUs running a streamlined version of the offline CMS reconstruction software. The operational L1 output rate of 100 kHz, together with the number of CPUs in the HLT farm, imposes a fundamental constraint on the amount of time available for the HLT to process events. Exceeding this limit impacts the experiment's ability to collect data efficiently. Hence, there is a critical need to characterize the performance of the HLT farm as well as the algorithms run prior to start up in order to ensure optimal data taking. Additional complications arise from the fact that the HLT farm consists of multiple generations of hardware and there can be subtleties in machine performance. We present our methods of measuring the timing performance of the CMS HLT, including the challenges of making such measurements. Results for the performance of various Intel Xeon architectures from 2009-2014 and different data taking scenarios are also presented. (paper)

  17. Initial experience with the CDF SVT trigger

    CERN Document Server

    Ashmanskas, B; Bardi, A; Bari, M; Baumgart, M; Belforte, S; Berryhill, J W; Bogdan, M; Carosi, R; Cerri, A; Chlachidze, G; Culberston, R; Dell'Orso, Mauro; Donati, S; Fiori, I; Frisch, H; Galeotti, S; Giannetti, P; Glagolev, V; Léger, A; Liu, Y; Meschi, E; Moneta, L; Morsani, F; Nakaya, T; Punzi, G; Rescigno, M; Ristori, L; Sanders, H; Sarkar, S; Semenov, A; Shochet, M; Speer, T; Spinella, F; Vataga, H; Wu, X; Yang, U; Zanello, L; Zanetti, A M

    2003-01-01

    The Collider Detector at Fermilab (CDF) Silicon Vertex Tracker (SVT) is a device that works inside the CDF Level 2 trigger to find and fit tracks in real time using the central silicon vertex detector information. SVT starts from tracks found by the Level 1 central chamber fast trigger and adds the silicon information to compute transverse track parameters with offline quality in about 15 mu s. The CDF SVT is fully installed and functional and has been exercised with real data during the spring and summer 2001. It is a complex digital device of more than 100 VME boards that performs a dramatic data reduction (only about one event in a thousand is accepted by the trigger). Diagnosing rare failures poses a special challenge and SVT internal data flow is monitored by dedicated hardware and software. This paper briefly covers the SVT architecture and design and reports on the SVT building/commissioning experience (hardware and software) and on the first results from the initial running.

  18. Initial experience with the CDF SVT trigger

    Science.gov (United States)

    Ashmanskas, B.; Barchiesi, A.; Bardi, A.; Bari, M.; Baumgart, M.; Belforte, Stefano; Berryhill, J.; Bogdan, M.; Carosi, R.; Cerri, A.; Chlachidze, G.; Culberston, R.; Dell'Orso, M.; Donati, S.; Fiori, I.; Frisch, H.; Galeotti, S.; Giannetti, P.; Glagolev, V.; Leger, A.; Liu, Y.; Meschi, E.; Moneta, L.; Morsani, F.; Nakaya, T.; Punzi, G.; Rescigno, M.; Ristori, L.; Sanders, H.; Sarkar, S.; Semenov, A.; Shochet, M.; Speer, T.; Spinella, F.; Vataga, H.; Wu, X.; Yang, U.; Zanello, L.; Zanetti, A. M.

    2003-03-01

    The Collider Detector at Fermilab (CDF) Silicon Vertex Tracker (SVT) is a device that works inside the CDF Level 2 trigger to find and fit tracks in real time using the central silicon vertex detector information. SVT starts from tracks found by the Level 1 central chamber fast trigger and adds the silicon information to compute transverse track parameters with offline quality in about 15 μs. The CDF SVT is fully installed and functional and has been exercised with real data during the spring and summer 2001. It is a complex digital device of more than 100 VME boards that performs a dramatic data reduction (only about one event in a thousand is accepted by the trigger). Diagnosing rare failures poses a special challenge and SVT internal data flow is monitored by dedicated hardware and software. This paper briefly covers the SVT architecture and design and reports on the SVT building/commissioning experience (hardware and software) and on the first results from the initial running.

  19. Mobile-phone pulse triggers evoked potentials.

    Science.gov (United States)

    Carrubba, Simona; Frilot, Clifton; Chesson, Andrew L; Marino, Andrew A

    2010-01-18

    If mobile-phone electromagnetic fields (EMFs) are hazardous, as suggested in the literature, processes or mechanisms must exist that allow the body to detect the fields. We hypothesized that the low-frequency pulses produced by mobile phones (217 Hz) were detected by sensory transduction, as evidenced by the ability of the pulses to trigger evoked potentials (EPs). Electroencephalograms (EEGs) were recorded from six standard locations in 20 volunteers and analyzed to detect brain potentials triggered by a pulse of the type produced by mobile phones. Evoked potentials having the expected latency were found in 90% of the volunteers, as assessed using a nonlinear method of EEG analysis. Evoked potentials were not detected when the EEG was analyzed using time averaging. The possibility of systematic error was excluded by sham-exposure analyses. The results implied that mobile-phones trigger EP at the rate of 217 Hz during ordinary phone use. Chronic production of the changes in brain activity might be pertinent to the reports of health hazards among mobile-phone users. (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  20. Ciprofloxacin triggered glutamate production by Corynebacterium glutamicum.

    Science.gov (United States)

    Lubitz, Dorit; Wendisch, Volker F

    2016-10-07

    Corynebacterium glutamicum is a well-studied bacterium which naturally overproduces glutamate when induced by an elicitor. Glutamate production is accompanied by decreased 2-oxoglutatate dehydrogenase activity. Elicitors of glutamate production by C. glutamicum analyzed to molecular detail target the cell envelope. Ciprofloxacin, an inhibitor of bacterial DNA gyrase and topoisomerase IV, was shown to inhibit growth of C. glutamicum wild type with concomitant excretion of glutamate. Enzyme assays showed that 2-oxoglutarate dehydrogenase activity was decreased due to ciprofloxacin addition. Transcriptome analysis revealed that this inhibitor of DNA gyrase increased RNA levels of genes involved in DNA synthesis, repair and modification. Glutamate production triggered by ciprofloxacin led to glutamate titers of up to 37 ± 1 mM and a substrate specific glutamate yield of 0.13 g/g. Even in the absence of the putative glutamate exporter gene yggB, ciprofloxacin effectively triggered glutamate production. When C. glutamicum wild type was cultivated under nitrogen-limiting conditions, 2-oxoglutarate rather than glutamate was produced as consequence of exposure to ciprofloxacin. Recombinant C. glutamicum strains overproducing lysine, arginine, ornithine, and putrescine, respectively, secreted glutamate instead of the desired amino acid when exposed to ciprofloxacin. Ciprofloxacin induced DNA synthesis and repair genes, reduced 2-oxoglutarate dehydrogenase activity and elicited glutamate production by C. glutamicum. Production of 2-oxoglutarate could be triggered by ciprofloxacin under nitrogen-limiting conditions.