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[en] Cosmic-ray proton and helium spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass experiment flown for 42 days in Antarctica in the 2004-2005 austral summer season. High-energy cosmic-ray data were collected at an average altitude of ∼38.5 km with an average atmospheric overburden of ∼3.9 g cm-2. Individual elements are clearly separated with a charge resolution of ∼0.15 e (in charge units) and ∼0.2 e for protons and helium nuclei, respectively. The measured spectra at the top of the atmosphere are represented by power laws with a spectral index of -2.66 ± 0.02 for protons from 2.5 TeV to 250 TeV and -2.58 ± 0.02 for helium nuclei from 630 GeV nucleon-1 to 63 TeV nucleon-1. They are harder than previous measurements at a few tens of GeV nucleon-1. The helium flux is higher than that expected from the extrapolation of the power law fitted to the lower-energy data. The relative abundance of protons to helium nuclei is 9.1 ± 0.5 for the range from 2.5 TeV nucleon-1 to 63 TeV nucleon-1. This ratio is considerably smaller than the previous measurements at a few tens of GeV nucleon-1.
[en] We estimate the expected flux of ultrahigh-energy (> 1018eV) protons in the present epoch due to a process which involves collapse or multiple self-intersections of a special class of closed cosmic string loops in the universe. We compare this flux with the observed flux of ultrahigh-energy cosmic rays, and discuss the implications. 19 refs., 1 fig
[en] Low-energy proton measurements associated with interplanetary MHD discontinuities were detected by the DFH instrument on ISEE-3 spacecraft during the solar maximum period of September 1978 to March 1980. The observations were made by three detectors, within eight sectors (each 45-deg wide) around the spacecraft, in eight energy channels extended from 35-1600 KeV. They confirm that local MHD conditions, especially discontinuities, significantly affect the propagation of low-energy particles in the interplanetary medium. 7 references
[en] An analysis of EGRET γ-ray data from the Compton Gamma Ray Observatory, together with data at other wavelengths, leads us to suggest that there are spectral variations of the proton component over the local Galaxy (within several hundred parsec of the Sun); most notably that the spectra are steeper in the Galactic interarm regions. The origin of the variations, if indeed they are substantiated, could be a combination of energetically- and spatially-variable diffusion properties and reacceleration of cosmic-ray particles. (author)
[en] The observation of high energy cosmic neutrinos can shed light on the astrophysical sites and mechanisms involved in the acceleration of protons and nuclei to the high energies observed at Earth by cosmic ray detectors. More generally, high energy neutrinos can be a key instrument in the multimessenger study of the high energy sky. Several neutrino telescopes of different sizes and capabilities are presently taking data and projects to further increase their size and sensitivity are underway. In this contribution we review the present status of neutrino telescopes based on the cherenkov ligh detection technique, their recent results and the plans to increase their sensitivity.
[en] IceTop is an instrument at the geographic South Pole designed to detect cosmic ray air showers, particle cascades in the atmosphere initiated by high-energy cosmic rays. It is the surface component of the IceCube neutrino telescope. Since its completion in December 2010, IceTop consists of 81 detector stations covering an area of one square kilometer on the ice surface above IceCube. Each IceTop station consists of two ice-filled tanks in which the Cherenkov light emitted by charged air shower particles is measured. In this dissertation, an analysis of data taken in 2007 with 26 IceTop stations operational at that time is presented. First, properties of air showers like core position, direction and shower size were reconstructed from the measured signals. The core position can be determined to an accuracy of up to 6m and a direction resolution of up to 0.3 is achieved. The shower size is a measure of the energy of the primary particle and a resolution of up to 10% is achieved at high energies. In the next step the relation between primary energy and shower size, as well as resolution and efficiency are determined from Monte Carlo simulations of air showers and the IceTop detector. Here, an assumption was made about the chemical composition of cosmic rays. The informations obtained in these simulations are then used to unfold the spectrum of measured shower sizes in order to obtain the all-particle cosmic ray energy spectrum. This is done independently for particles from three different zenith angle intervals. The result of the unfolding depends on the assumed primary composition. Due to the isotropy of cosmic rays, results obtained in different zenith angle intervals must agree. While with the chosen analysis technique a simultaneous determination of primary particle mass and energy is limited due to systematic uncertainties, it has already been shown that the requirement of isotropy can be used to constrain the range of possible assumptions on the chemical composition of primary particles. Good agreement of spectra from different zenith angle ranges has been found under the assumption of pure proton primaries, as well as for a mixture of protons and iron with a relatively large proton contribution at low energies and proton dominance at high energies. Under these assumptions the knee of the cosmic ray energy spectrum has been observed at energies between 3.97 and 4.20 PeV. The spectral index below the knee is about -2.7 and varies between -3.08 and -3.15 above the knee. Pure iron as primary particles can be excluded at a high confidence level below 25 PeV. Independent of the primary composition assumption a flattening of the energy spectrum with an index of about -3.0 has been observed above 30 PeV.
[en] The data of SOKOL, JACEE and MUBEE experiments are used to compare energy spectra of cosmic-ray protons and other nuclei. It is shown that the standard model with invariable chemical composition does not explain the experimental data above several TeV. The assumption that the cosmic-ray spectrum consists of two components of different origin and different nucleus composition is discussed. (author). Letter-to-the-editor
[en] We will examine modeling data for various orbits using modeling software and compare this with actual satellite flight result. In particular, we will discuss the contributions of trapped protons to total dose and the effectiveness of shielding
[en] We examine the possibility that the observed cosmic-ray protons are of primary extragalactic origin. The present anti p data are consistent with a primary extragalactic component having anti p/papprox.=3.2+-0.7x10-4 independent of energy. Following the suggestion that most extragalactic cosmic rays are from active galaxies, we propose that most of the observed anti p's are also from the same sites. This would imply the possibility of destroying the corresponding anti α's at the source, thus leading to a flux ratio anti α/α< anti p/p. We further predict an estimate for anti α/αproportional10-5, within the range of future cosmic-ray detectors. The cosmological implications of this proposal are discussed. (orig.)
[en] The effects of magnetic field turbulence on the anisotropy of galactic cosmic rays of the highest energies are investigated. It is found that, if the cosmic ray flux at energies above 1 EeV is made up predominantly of galactic protons, neither the observed galactic magnetic field turbulence nor possible halo turbulence are sufficient for both the computed anisotropy and galactic flux gradient to agree with observation. The implication is that the origin of these cosmic rays is not within our galaxy. (author)