Composition of solar cosmic rays.
Solar cosmic ray particle composition, charge and energy spectra of nuclear components and isotopic composition of H and He
HELIUM ATOM↗
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The cosmic ray anisotropy.
Cosmic ray anisotropy may be due to existence of trapped orbits in interplanetary field, sunward flux density gradient or Compton-Getting effect
RADIATION INTENSITY↗
Further studies of the isotopic composition of cosmic ray Li, Be and B nuclei - Implications for the cosmic ray age
The isotopic compositions of Li, Be, and B nuclei were investigated by using balloon flight data and the dE/dx X(E) mode of analysis. 600 Be nuclei were considered, including 24 (Be-10) isotopes; the effect of solar modulation of the surviving fraction of (Be-10) measured in this experiment and limits on the age of cosmic rays are discussed. The isotopic composition of all Li, Be, and B nuclei is examined with respect to the fragmentation origin of these particles and the effects of solar modulation.
Webber, W. R.↗
New Results on High Energy Cosmic Ray Electrons Observed with Fermi LAT and Their Implications on the Origin of Cosmic Rays
The Large Area Telescope on-board the Fermi Gamma-Ray Space Telescope has collected more than 10 million cosmic ray electrons with energy above 7 GeV since its science operation on orbit. High energy electrons rapidly lose their energy by synchrotron radiation on Galactic magnetic fields and by inverse Compton scattering on the interstellar radiation field. The typical distance over which a 1 TeV electron loses half its total energy is estimated to be 300-400 pc.This makes them a unique tool for probing nearby Galactic space. Observed spectrum has a harder spectral index than was previously reported and suggests the presence of nearby sources of high energy electrons. One of viable candidates are nearby pulsars, possibly some of recently discovered by Fermi. At the same time the dark matter origin of such sources cannot be ruled out. I will also report our current upper limits on cosmic ray electrons anisotropy which helps to set constraints on their local sources.
Moiseev, Alexander↗
Cosmic ray drift, shock wave acceleration and the anomalous component of cosmic rays
A model of the anomalous component of the quiet-time cosmic ray flux is presented in which ex-interstellar neutral particles are accelerated continuously in the polar regions of the solar-wind termination shock, and then drift into the equatorial regions of the inner heliosphere. The observed solar-cycle variations, radial gradient, and apparent latitude gradient of the anomalous component are a natural consequence of this model.
Pesses, M. E.↗
Cosmic ray drift, shock wave acceleration, and the anomalous component of cosmic rays
A model of the anomalous component of the quiet-time cosmic ray flux is presented in which ex-interstellar neutral particles are accelerated continuously in the polar regions of the solar-wind termination shock and then drift into the equatorial regions of the inner heliosphere. The observed solar-cycle variations, radial gradient, and apparent latitude gradient of the anomalous component are a natural consequence of this model.
Pesses, M. E.↗
A local recent supernova - Evidence from X-rays, Al-26 radioactivity and cosmic rays
Possible ways in which cosmic rays could have been contaminated by a local recent supernova are discussed, and ways in which this contamination may be affecting interpretation of Al-26 gamma radiation and locally observed cosmic rays as samples of the average Galactic distribution are considered. Mass spectra of cosmic rays are examined to see whether there is enrichment by a population arising from supernova preacceleration. The reinterpretation of the anomalous component in terms of a local supernova model is addressed.
Clayton, Donald D.↗
Variation of cosmic rays and solar wind properties with respect to the heliospheric current sheet. II - Rigidity dependence of the latitudinal gradient of cosmic rays at 1 AU
The role which empirical determinations of the latitudinal variation of cosmic rays with respect to the current sheet may have in illuminating the importance of the cross-field drift of particles in the large-scale heliospheric magnetic field is discussed. Using K coronameter observations and measured solar wind speeds, the latitudinal gradients have been determined with respect to the current sheet for cosmic rays in four rigidity ranges. Gradients vary between approximately -2 and -50 pct/AU. The rigidity dependence of the decrease of cosmic ray flux with distance from the current sheet lies between the -0.72 to -0.86 power of the rigidity, with the exact dependence being determined by the definition used for the median rigidity of each monitor.
Newkirk, G., Jr.↗
On cosmic ray cutoffs.
Cosmic ray cutoff in the stormer sense for high latitudes at which the geomagnetic field is approximately axisymmetric
COSMIC RADIATION↗
Effects of particle drift on the transport of cosmic rays. III - Numerical models of galactic cosmic-ray modulation
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Jokipii, J. R.↗
Gamma-ray astronomy and the origin of cosmic rays
Recent observations of cosmic gamma radiation are reviewed. It is shown that this radiation consists of an extragalactic background as well as a bright band of galactic radiation lying in the plane of the Milky Way and produced primarily by cosmic-ray collisions with interstellar gas atoms. The galactic gamma radiation is divided into a near component apparently associated with Gould's belt and a far component originating about 15,000 light years away and narrowly confined to the galactic plane. A Great Galactic Ring is identified which is 35,000 light years in diameter and in which most galactic cosmic rays are produced and supernovae and pulsars are concentrated. The physical mechanisms responsible for the production of most of the cosmic gamma rays in the Galaxy are examined, and the origin of galactic cosmic rays is considered. It is concluded that the cosmic rays are produced either in supernova explosions or in the pulsars they leave behind
Stecker, F. W.↗
Progress in the measurement of high-energy galactic cosmic ray electrons
Cosmic ray electron measurements by individual threshold detector elements show that about 30 percent of observed electron-like galactic cosmic showers are really proton initiated events. The cosmic electron spectrum at about 10 GeV exhibits a consistent dropoff in intensity leading to a best fit at a power law of spectral index -3.2; a break in the spectrum should occur above 10 GeV.
Silverberg, R. F.↗
Cosmic-ray telescope
Cosmic ray telescope to measure absolute and relative flux levels and energy spectra of two main components of primary radiation
TELESCOPE↗
On the relationship between recent measurements of cosmic ray electrons, nonthermal radio emission from the Galaxy, and the solar modulation of cosmic rays.
Local interstellar electron spectrum limits from measurements of cosmic ray electrons, nonthermal galactic radio emission and solar modulation effects
Webber, W. R.↗
Cosmic ray exposure ages of chondrites, pre-irradiation and constancy of cosmic ray flux in the past
Calibration of the production rate of the Ne-21 nuclide was accomplished by 4 methods based on (Al-26)-age, (Mn-53)-age, Kr-81/Kr-83, and Na-22/Ne-22. These production rates are normalized to a shielding parameter ratio Ne-22/Ne-21 = 1.11 and to the chemical composition of L chondrites; a value of P(21)(1.11) = 0.31 is suggested, and a production rate equation derived in terms of the 'F' parameters for L, LL, and H chondrites. The Al-26 half-life measurements are considered to evaluate the effects resulting from preirradiation of meteorites and to examine the data on the constancy of the cosmic ray flux in the light of current astronomical observations.
Nishizumi, K.↗
An improved model for cosmic-ray propagation.
Cosmic ray propagation Jokipii model modification, taking into account particle mirroring to determine diffusion coefficient by limited portion of field spectrum
Noerdlinger, P. D.↗
Cosmic-ray propagation.
Cosmic ray propagation, discussing interstellar matter effect on composition and diffusion effect necessary to study radiation models
Fichtel, C. E.↗