28 research outputs found

    AMANDA Observations Constrain the Ultra-High Energy Neutrino Flux

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    A number of experimental techniques are currently being deployed in an effort to make the first detection of ultra-high energy cosmic neutrinos. To accomplish this goal, techniques using radio and acoustic detectors are being developed, which are optimally designed for studying neutrinos with energies in the PeV-EeV range and above. Data from the AMANDA experiment, in contrast, has been used to place limits on the cosmic neutrino flux at less extreme energies (up to ~10 PeV). In this letter, we show that by adopting a different analysis strategy, optimized for much higher energy neutrinos, the same AMANDA data can be used to place a limit competitive with radio techniques at EeV energies. We also discuss the sensitivity of the IceCube experiment, in various stages of deployment, to ultra-high energy neutrinos.Comment: 4 pages, 3 figure

    Operation Of The NuMi Beam Monitoring System

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    The NuMI (Neutrinos at the Main Injector) facility produces an intense neutrino beam for experiments. The NuMI Beam Monitoring system consists of four arrays of ion chambers that measure the intensity and distribution of the remnant hadron and tertiary muon beams produced in association with the neutrinos. The ion chambers operate in an environment of high particle fluxes and high radiation.Physic

    Report of the 2005 Snowmass Top/QCD Working Group

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    This report discusses several topics in both top quark physics and QCD at an International Linear Collider (ILC). Issues such as measurements at the ttˉt\bar{t} threshold, including both theoretical and machine requirements, and the determination of electroweak top quark couplings, are reviewed. New results concerning the potential of a 500 GeV e+ee^+e^- collider for measuring WtbWtb couplings and the top quark Yukawa coupling are presented. The status of higher order QCD corrections to jet production cross sections, heavy quark form factors, and longitudinal gauge boson scattering, needed for percent-level studies at the ILC, are reviewed. A new study of the measurement of the hadronic structure of the photon at a γγ\gamma\gamma collider is presented. The effects on top quark properties from several models of new physics, including composite models, Little Higgs theories, and CPT violation, are studied.Comment: 39 pages, many figs; typos fixed and refs added. Contributed to the 2005 International Linear Collider Physics and Detector Workshop and 2nd ILC Accelerator Workshop, Snowmass, Colorado, 14-27 Aug 200

    Pulsed Energy Storage System Design

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    A superconductive energy storage magnet which is connected to the three phase power system could be designed, constructed, and placed in operation at Fermilab which would essentially eliminate the large repetitive power pulses now required from the power system. In addition to the power pulses, voltage flicker is also caused due to the reactive power pulsation. Specifically, a one megawatt hour superconductive energy storage magnet and a 2.00 megawatt thyristorized converter can achieve nullification of these power pulses up to 400 GEV synchrotron operation. Above 400 GEV, operation should be possible up to 500 GEV with appreciable less power pulsing requirements from the system than are now considered permissible. Carried to successful completion, this project would serve to advance applied superconductivity to a highly significant degree. The effect would be of world wide importance to both high energy physics and to the electric power industry. The preliminary magnet design is a 1 MWh dipole composed of cryogenically stable composite conductors connected in parallel with aluminum shield windings. The shield windings carry impressed pulsed currents while eliminating pulsed currents from the dc superconductive windings. Without pulsed currents or pulsed magnetic fields there are no ac losses in standard helium. The major radius of the dipole is 8.85 m; the minor radius is 0.69m; there are 188 turns at 80,000 A and each turn is 4 conductors wound in parallel. The 20,000 A TiNb-copper composite conductor is l0x 1.12 cm in cross section similar to but larger than the FNAL bubble chamber conductor. The shield is 188 turns (equal number of turns is a shielding condition) of hollow aluminum conductor cooled via circulated cold helium gas at 40K. The turns are spaced around the minor circumference according to a cosine distribution which produces zero internal field. In use the shield loss converted to room temperature power is about .8MW when 0.1 MWh is used from a 1 MWh storage dipole. The 0.1 MWh is sufficient to provide complete load leveling for 400 GEV pulses, and operation at 500 GEV with lower power transients than are presently experienced

    The pilot way to Grid resources using glideinWMS

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    Grid computing has become very popular in big and widespread scientific communities with high computing demands, like high energy physics. Computing resources are being distributed over many independent sites with only a thin layer of Grid middleware shared between them. This deployment model has proven to be very convenient for computing resource providers, but has introduced several problems for the users of the system, the three major being the complexity of job scheduling, the nonuniformity of computer resources, and the lack of good job monitoring. Pilot jobs address all the above problems by creating a virtual private computing pool on top of Grid resources. This paper presents both the general pilot concept, as well as a concrete implementation, called glideinWMS, deployed in the Open Science Grid
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