995 research outputs found

    In ice radio detection of GZK neutrinos

    Get PDF
    Models for the source and propagation of cosmic rays are stressed by observations of cosmic rays with energies E>1020E>10^{20} eV. A key discriminant between different models may be complementary observations of neutrinos with energies E>1018E>10^{18} eV. Independent of the source of the cosmic rays, neutrinos are produced during propagation via the GZK mechanism. Event rates for GZK neutrinos are expected to be in the range of 0.01−0.10.01-0.1 per km3^3 yr, suggesting a detector mass in excess of 1 Eg. Detection of radio cherenkov emission from showers produced in Antarctic ice may be an economical way to instrument such a large mass. It is suggested that a 100 km2^2 array of antennas centered on Icecube may allow confirmation of the radio technique and also increase the science achievable with Icecube by providing vertex information for events with throughgoing muons.Comment: 8 pages, 3 figures, to be published in proceedings of RADHEP-200

    An analysis and simulation of landings utilizing stored-energy lift Final report, May 12 - Nov. 30, 1967

    Get PDF
    Computerized simulation of aircraft landing deceleration with stored energy lif

    In-flight simulation study of decoupled longitudinal controls for the approach and landing of a STOL aircraft

    Get PDF
    In this decoupled concept, the natural interactions of the flight variables were suppressed, and the pilot operated a separate controller for each (fore-and-aft control column for flight path angle without speed or pitch attitude change, for example). The handling qualities of the decoupled airplane were judged to be very favorable. The precise path control led to small touchdown point dispersion along with consistently low sink rates. The decoupled control system provided significantly better flying qualities than did conventional SAS applied to the same basic airframe

    Integrated lift/drag controller for aircraft

    Get PDF
    A system for altering the lift/drag characteristics of powered aircraft to provide a safe means of glide path control includes a control device integrated for coordination action with the aircraft throttle. Such lift/drag alteration devices as spoilers, dive brakes, and the like are actuated by manual operation of a single lever coupled with the throttle for integrating, blending or coordinating power control. Improper operation of the controller is inhibited by safety mechanisms

    Cosmic ray albedo gamma rays from the quiet sun

    Get PDF
    We estimate the flux of gamma-rays that result from collisions of high energy galactic cosmic rays with the solar atmosphere. An important aspect of our model is the propagation of cosmic rays through the magnetic fields of the inner solar systems. We use diffusion to model propagation down to the bottom of the corona. Below the corona we trace particle orbits through the photospheric fields to determine the location of cosmic ray interactions in the solar atmosphere and evolve the resultant cascades. For our nominal choice of parameters, we predict an integrated flux of gamma rays (at 1 AU) of F(E(sub gamma) greater than 100 MeV) approximately = 5 x 10(exp -8)/sq cm sec. This can be an order of magnitude above the galactic background and should be observable by the Energetic Gamma Ray experiment telescope (EGRET)

    Integrated flight controller for light aircraft

    Get PDF
    Controller-throttle engages spoiler/dive brake system when throttle setting is below a fixed power setting and gradually increases effect of spoiler/dive brake as throttle is moved toward idle position; since action is automatically reversible, a sudden application of power abruptly terminates aerodynamic effects of spoiler/dive brake system

    An Isocurvature CDM Cosmogony. I. A Worked Example of Evolution Through Inflation

    Full text link
    I present a specific worked example of evolution through inflation to the initial conditions for an isocurvature CDM model for structure formation. The model invokes three scalar fields, one that drives power law inflation, one that survives to become the present-day CDM, and one that gives the CDM field a mass that slowly decreases during inflation and so ``tilts'' the primeval mass fluctuation spectrum of the CDM. The functional forms for the potentials and the parameter values that lead to an observationally acceptable model for structure formation do not seem to be out of line with current ideas about the physics of the very early universe. I argue in an accompanying paper that the model offers an acceptable fit to main observational constraints.Comment: 11 pages, 3 postscript figures, uses aas2pp4.st

    The anthropic principle and the mass scale of the Standard Model

    Get PDF
    In theories in which different regions of the universe can have different values of the the physical parameters, we would naturally find ourselves in a region which has parameters favorable for life. We explore the range of anthropically allowed values of the mass parameter in the Higgs potential, μ2\mu^2. For μ2<0\mu^2<0, the requirement that complex elements be formed suggests that the Higgs vacuum expectation value vv must have a magnitude less than 5 times its observed value. For μ2>0\mu^2>0, baryon stability requires that ∣μ∣<<MP|\mu|<<M_P, the Planck Mass. Smaller values of ∣μ2∣|\mu^2| may or may not be allowed depending on issues of element synthesis and stellar evolution. We conclude that the observed value of μ2\mu^2 is reasonably typical of the anthropically allowed range, and that anthropic arguments provide a plausible explanation for the closeness of the QCD scale and the weak scale.Comment: 28 pages, LaTeX. No changes from version originally submitted to archive, except that problem with figure file has been correcte
    • …
    corecore