Composition and energy spectra of cosmic rays—Implications for cosmic ray origins

1997 ◽  
Author(s):  
Michael L. Cherry
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Energy Spectra

The effects of the nature of matter traversed by cosmic rays on their composition and energy spectrum

1968 ◽  
Vol 46 (10) ◽  
pp. S512-S514
Author(s):  
M. V. K. Apparao ◽  
S. Ramadurai
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Neutral Hydrogen ◽  
Cosmic Ray ◽  
The State ◽  
Energy Spectra ◽  
Ionization Loss ◽  
Usual Assumption ◽  
Considerable Portion ◽  
Nature Of Matter

The effects of the state of ionization of the matter traversed by cosmic rays, and those due to the presence of helium in it, have been studied. The amount of matter traversed by cosmic rays expressed in g/cm2 deduced by the usual assumption that the matter traversed is all neutral hydrogen can be erroneous. The presence of helium increases this value, and a considerable portion of the matter is helium. The ionized (partial) nature of the matter increases the ionization loss of cosmic-ray nuclei. The effect of this on energy spectra has been demonstrated.

Particle Acceleration in the Disk-Halo System

1991 ◽  
Vol 144 ◽  
pp. 377-386
Author(s):  
Reinhard Schlickeiser
Keyword(s):  
Particle Acceleration ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Energy Spectra ◽  
Galactic Wind ◽  
Γ Rays ◽  
Γ Ray

The recent observations of the nonthermal properties of the halo of our Galaxy at radio and γ-ray wavelengths are summarized. Radio and γ-ray data show a similar spectral flattening with Galactic height towards the anticenter direction, which is interpreted as a cosmic-ray effect. Several theoretical explanations for the flattening of the energy spectra of the radiating cosmic-ray electrons (in the radio) and nucleons (in γ-rays) are reviewed including propagation of cosmic rays in an accelerating Galactic wind and the presence of cosmic-ray sources with flat energy spectra in the halo.

ENERGY SPECTRA AND MASS COMPOSITION OF COSMIC RAYS IN THE FRACTAL-LIKE GALACTIC MEDIUM

2005 ◽  
Vol 20 (29) ◽  
pp. 6834-6836 ◽  
Author(s):  
A. A. LAGUTIN ◽  
A. G. TYUMENTSEV ◽  
A. V. YUSHKOV
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Energy Spectra ◽  
Mass Composition ◽  
Primary Spectrum ◽  
Composition Variation ◽  
Region 10 ◽  
Basic Features ◽  
Galactic Sources ◽  
Knee Problem

We consider the problem of the cosmic ray spectrum formation assuming that cosmic rays are produced by galactic sources. The fractional diffusion equation proposed in our recent papers is used to describe the cosmic rays propagation in interstellar medium. We show that in the framework of this approach it is possible to explain the locally observed basic features of the cosmic rays in the energy region 1010 ÷ 1020 eV : difference between spectral exponents of protons and other nuclei, mass composition variation, "knee" problem, flattening of the primary spectrum for E ≥ 1018 ÷ 1019 eV .

scholarly journals Energy spectra of carbon and oxygen with HELIOS E6

2018 ◽  
Vol 610 ◽  
pp. A42 ◽  
Author(s):  
J. Marquardt ◽  
B. Heber ◽  
M. S. Potgieter ◽  
R. D. Strauss
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Energy Spectra ◽  
Quiet Time ◽  
Transport Models ◽  
Radial Gradient ◽  
The One ◽  
Galactic Cosmic Ray ◽  
Good Agreement ◽  
Inner Heliosphere

Context. Anomalous cosmic rays (ACRs) are well-suited to probe the transport conditions of cosmic rays in the inner heliosphere. We revisit the HELIOS data not only in view of the upcoming Solar Orbiter experiment but also to put constraints on particle transport models in order to provide new insight into the boundary conditions close to the Sun. Aims. We present here the energy spectra of galactic cosmic ray (GCR) carbon and oxygen, as well as of ACR oxygen during solar quiet time periods between 1975 to 1977, utilizing both HELIOS spacecraft at distances between ~0.3 and 1 AU. The radial gradient (Gr ≈ 50%/AU) of 9–28.5 MeV ACR oxygen in the inner heliosphere is about three times larger than the one determined between 1 and 10 AU by utilizing the Pioneer 10 measurements. Methods. The chemical composition as well as the energy spectra have been derived by applying the dE∕dx − E-method. In order to derive these values, special characteristics of the instrument have been taken into account. Results. A good agreement of the GCR energy spectra of carbon and oxygen measured by the HELIOS E6 instrument between 0.3 and 1 AU and the Interplanetary Monitoring Platform (IMP) 8 at 1 AU was found. For ACR oxygen, we determined a radial gradient of about 50%/AU that is three times larger than the one between 7 and 14 AU, indicating a strong change in the inner heliosphere.

Propagation of Ultra-High Energy Cosmic Rays in Extragalactic Magnetic Fields

Open Physics ◽  
2004 ◽  
Vol 2 (2) ◽  
Author(s):  
Tadeusz Wibig
Keyword(s):  
Cosmic Rays ◽  
Magnetic Fields ◽  
Cosmic Ray ◽  
High Energy ◽  
Source Model ◽  
Energy Spectra ◽  
Single Source ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
Open Question

AbstractIn this paper we will discuss the problem of Ultra High Energy Cosmic Rays (UHECR) and show that the idea of a Single Source Model established by Erlykin and Wolfendale (1997) to explain the features seen in cosmic ray energy spectra around the 1015 eV region can be successfully applied also for the much higher energies. The propagation of UHECR (of energies higher than 1019 eV) in extragalactic magnetic fields can no longer be described as a random walk (diffusion) process and the transition to rectilinear propagation gives a possible explanation for the so-called Greisen-Zatzepin-Kuzmin (GZK) cut-off which still remains an open question after almost 40 years. A transient “single source” located at a particular distance and producing UHECR for a finite time is the proposed solution.

scholarly journals CR-39 Plastic Track Detector Experiment for Measurement of Charge Composition of Primary Cosmic Rays

1981 ◽  
Vol 94 ◽  
pp. 37-38
Author(s):  
Y. V. Rao ◽  
A. Davis ◽  
M. P. Hagan ◽  
R. C. Filz
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Track Detector ◽  
Energy Spectra ◽  
Charge Composition ◽  
Significant Information ◽  
Residual Atmosphere ◽  
New Type ◽  
Air Force Base ◽  
Primary Cosmic Rays

A study of the relative abundances and energy spectra of heavy cosmic rays and isotopic composition in the region of Fe peak can yield significant information concerning their origin, acceleration and interstellar propagation. In recent years solid state nuclear track detectors have been employed extensively to study heavy primary cosmic rays. Plastic track detectors necessarily have large geometric factors for heavy primaries, and a continuous sensitivity for the duration of an extended exposure. A balloon-borne experiment consisting of 1 m2 passive detector array has been designed in order to obtain charge and energy spectra of primary cosmic rays in the region of Fe peak. Included in the array is a new type of nuclear-track-recording plastic, a polymer made from the monomer allyl diglycol carbonate (commercially known as CR-39). The stack was built as a set of nine modules. Three types of stack assembly was adopted for these modules: one consisting of ‘pure’ CR-39 plastic track detector: the next one, a composite assembly of CR-39 with three layers of 600 micron thick nuclear emulsions: and the last one with CR-39 and Lexan Polycarbonate. The payload was flown successfully in June 1979 from Eielson Air Force Base, Alaska. The flight was aloft for 3 hours 30 min at an average ceiling of 3 gm/cm2 of residual atmosphere. An attempt to stabilize and orient the payload utilizing a biaxial magnetometer combined with and electrical rotator was unsuccessful. The failure to orient the payload in a stable position would prevent us from determining the true direction of each cosmic ray particle and trace it backwards through the earth's magnetic field using a computer tracing program. Recovery of the payload was routine and all materials were in perfect condition.

Two anisotropies of the cosmic-ray particles producing the cosmic-ray diurnal variation

1968 ◽  
Vol 46 (10) ◽  
pp. S828-S830
Author(s):  
Masatoshi Kitamura
Keyword(s):  
Cosmic Rays ◽  
Diurnal Variation ◽  
Interplanetary Space ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Diurnal Variations ◽  
Low Energy ◽  
The Other ◽  
Energy Spectra ◽  
Cosmic Ray Intensity

The solar diurnal variations of both meson and nucleon components of cosmic rays at sea level at geomagnetic latitude 57.5° and geomagnetic longitude 0° are analyzed by the model in which two anisotropies of cosmic-ray particles (one of them, Δj1, from about 20 h L.T. and the other, Δj2, from about 8 h L.T. in interplanetary space) produce the solar diurnal variation of the cosmic-ray intensity on the earth.When the energy spectra of Δj1 and Δj2 are represented by [Formula: see text] and [Formula: see text], respectively, where j0(E) is the normal energy spectrum of the primary cosmic rays, it is shown that the evaluation for m1 = 1, 2, m2 = 0 and the cutoffs at 8 and 10 BeV on the low-energy side of spectra of both Δj1 and Δj2 agree well with the observational results at Deep River.

Charge and energy spectra of cosmic-ray nuclei with Z = 10–28

1968 ◽  
Vol 46 (10) ◽  
pp. S588-S592 ◽  
Author(s):  
V. S. Bhatia ◽  
V. S. Chohan ◽  
S. D. Pabbi ◽  
S. Biswas
Keyword(s):  
Cosmic Rays ◽  
Nuclear Charge ◽  
Cosmic Ray ◽  
Energy Spectra ◽  
Charge Composition ◽  
Improved Method ◽  
Residual Atmosphere ◽  
Primary Ionization ◽  
Charge Determination

An improved method of charge determination of heavy primary cosmic rays of nuclear charge Z = 10–28 has been obtained by measuring the Fowler–Perkins parameter in less-sensitive G-2 and G-0 emulsions for the determination of the primary ionization. It is found that reliable measurements of the primary ionization can be made for ionizations as high as ~1 000 times minimum. The average errors in the charge determinations by this method were found to be about 0.5, 0.7, and 1.0 unit of charge for H1 (Z = 10–15), H2 (Z = 16–19), and H3 (Z = 20–30) groups of nuclei, respectively. This method has been applied to the study of the H1, H2, and H3 groups of nuclei in an emulsion stack exposed over Fort Churchill, Canada, on June 18, 1963 at 4.3 g cm−2 of residual atmosphere for 11.1 h. The results are based on an analysis of 340 nuclei with [Formula: see text]. The charge composition and relative abundances of the H1, H2, and H3 nuclei were obtained. The differential energy spectra of the H1, H2, H3, and [Formula: see text] groups of nuclei were determined in the energy interval 250–1 000 MeV/nucleon and integral fluxes for energy > 1 000 MeV/nucleon.

The composition of low-energy cosmic rays in 1965

1968 ◽  
Vol 46 (10) ◽  
pp. S539-S543 ◽  
Author(s):  
D. E. Hagge ◽  
V. K. Balasubrahmanyan ◽  
F. B. McDonald
Keyword(s):  
Cosmic Rays ◽  
Energy Range ◽  
Cosmic Ray ◽  
Low Energy ◽  
Oxygen Flux ◽  
Energy Spectra ◽  
Solar Modulation ◽  
Charge Composition ◽  
Specific Component ◽  
Relative Abundances

Primary cosmic-ray energy spectra and charge composition have been measured during the 1965 period of solar modulation minimum. A dE/dx vs. E type of scintillator–photomultiplier detector on board the eccentric-orbiting NASA spacecraft OGO-I was used. The charge composition was measured through neon over an energy range of 25 to 200 MeV/nucleon, depending upon the specific component. The spectra for all groups are nearly flat during this time, with the oxygen flux at about 0.005 nucleus/(M2-sr-s-MeV/nucleon). The relative abundances found are Li, 0.27; Be, 0.11; B, 0.37; C, 1.20; N, 0.30; O 1.00; F, [Formula: see text]; Ne, 0 12 An L/M ratio of 0.30 ± 0.06 is found.

scholarly journals PRECISE COSMIC RAYS MEASUREMENTS WITH PAMELA

2013 ◽  
Vol 53 (A) ◽  
pp. 712-717
Author(s):  
A. Bruno ◽  
O. Adriani ◽  
G. C. Barbarino ◽  
G. A. Bazilevskaya ◽  
R. Bellotti ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Secondary Production ◽  
Cosmic Ray ◽  
Light Nuclei ◽  
Energy Spectra ◽  
Wide Energy Range ◽  
Pamela Experiment ◽  
Production Models ◽  
The Galaxy ◽  
Wide Energy

The PAMELA experiment was launched on board the Resurs-DK1 satellite on June 15th 2006. The apparatus was designed to conduct precision studies of charged cosmic radiation over a wide energy range, from tens of MeV up to several hundred GeV, with unprecedented statistics. In five years of continuous data taking in space, PAMELA accurately measured the energy spectra of cosmic ray antiprotons and positrons, as well as protons, electrons and light nuclei, sometimes providing data in unexplored energetic regions. These important results have shed new light in several astrophysical fields like: an indirect search for Dark Matter, a search for cosmological antimatter (anti-Helium), and the validation of acceleration, transport and secondary production models of cosmic rays in the Galaxy. Some of the most important items of Solar and Magnetospheric physics were also investigated. Here we present the most recent results obtained by the PAMELA experiment.

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