SOME ASPECTS OF THE PROPAGATION OF SUPER-HIGH ENERGETIC COSMIC RAYS IN THE GALAXY

2005 ◽  
Vol 20 (29) ◽  
pp. 6825-6827
Author(s):  
JÖRG R. HÖRANDEL ◽  
NIKOLAI N. KALMYKOV ◽  
ALEKSEI V. TIMOKHIN
Keyword(s):  
Experimental Data ◽  
Energy Spectrum ◽  
Cosmic Rays ◽  
Life Time ◽  
High Energy ◽  
Energy Spectra ◽  
Combined Method ◽  
High Energy Astrophysics ◽  
The Galaxy ◽  
Energy Dependent

The origin of the knee in the energy spectrum of cosmic rays is one of the central questions of high-energy astrophysics. One possible explanation is the energy dependent leakage of nuclei from the Galaxy due to their propagation. The latter is investigated in a combined method using numerical calculations of trajectories and the diffusion approximation. The life time of cosmic rays in the Galaxy and the corresponding pathlength are presented. The resulting energy spectra as observed at Earth are discussed and compared to experimental data.

scholarly journals Composition and Galactic Confinement of Cosmic Rays

1971 ◽  
Vol 2 ◽  
pp. 740-756
Author(s):  
Maurice M. Shapiro
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Interstellar Space ◽  
Heavy Nuclei ◽  
High Energy Astrophysics ◽  
Transit Times ◽  
The Galaxy ◽  
Path Lengths

The ‘Galactic’ cosmic rays impinging on the Earth come from afar over tortuous paths, traveling for millions of years. These particles are the only known samples of matter that reach us from regions of space beyond the solar system. Their chemical and isotopic composition and their energy spectra provide clues to the nature of cosmic-ray sources, the properties of interstellar space, and the dynamics of the Galaxy. Various processes in high-energy astrophysics could be illuminated by a more complete understanding of the arriving cosmic rays, including the electrons and gamma rays.En route, some of theprimordialcosmic-ray nuclei have been transformed by collision with interstellar matter, and the composition is substantially modified by these collisions. A dramatic consequence of the transformations is the presence in the arriving ‘beam’ of considerable fluxes of purely secondary elements (Li, Be, B), i.e., species that are, in all probability, essentially absent at the sources. We shall here discuss mainly the composition of the arriving ‘heavy’ nuclei -those heavier than helium - and what they teach us about thesourcecomposition, the galactic confinement of the particles, their path lengths, and their transit times.

scholarly journals High energy cosmic ray interactions and UHECR composition problem

2019 ◽  
Vol 210 ◽  
pp. 02001
Author(s):  
Sergey Ostapchenko
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Hadronic Interactions ◽  
High Energy Cosmic Rays ◽  
Cosmic Ray Interactions ◽  
Composition Problem

The differences between contemporary Monte Carlo generators of high energy hadronic interactions are discussed and their impact on the interpretation of experimental data on ultra-high energy cosmic rays (UHECRs) is studied. Key directions for further model improvements are outlined. The prospect for a coherent interpretation of the data in terms of the UHECR composition is investigated.

Energy spectrum and mass composition of high-energy cosmic rays

2003 ◽  
Vol 66 (7) ◽  
pp. 1145-1206 ◽  
Author(s):  
Andreas Haungs ◽  
Heinigerd Rebel ◽  
Markus Roth
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
High Energy ◽  
Mass Composition ◽  
High Energy Cosmic Rays

ULTRA HIGH ENERGY COSMIC RAYS WITH THE PIERRE AUGER OBSERVATORY

2012 ◽  
Vol 18 ◽  
pp. 221-229
Author(s):  
◽  
J. R. T. DE MELLO NETO
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Cross Section ◽  
High Energy ◽  
Pierre Auger Observatory ◽  
Mass Composition ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
The Status ◽  
Shower Maximum

We present the status and the recent measurements from the Pierre Auger Observatory. The energy spectrum is described and its features discussed. We report searches for anisotropy of cosmic rays arrival directions in large scales and through correlation with catalogues of celestial objects. The measurement of the cross section proton-air is discussed. Finally, the mass composition is addressed with the measurements of the variation of the depth of shower maximum with energy and with the muon density at ground.

Diffraction properties of a strongly bent diamond crystal used as a dispersive spectrometer for XFEL pulses

2019 ◽  
Vol 26 (4) ◽  
pp. 1069-1072 ◽  
Author(s):  
Liubov Samoylova ◽  
Ulrike Boesenberg ◽  
Aleksandr Chumakov ◽  
Vladimir Kaganer ◽  
Ilia Petrov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Energy Spectrum ◽  
Strain Gradient ◽  
Free Electron ◽  
Diamond Crystal ◽  
Energy Spectra ◽  
Theoretical Modelling ◽  
Free Electron Lasers ◽  
X Ray ◽  
Stochastic Nature

Self-amplified spontaneous emission (SASE) enables X-ray free-electron lasers (XFELs) to generate hard X-ray pulses of sub-100 fs duration. However, due to the stochastic nature of SASE, the energy spectrum fluctuates from pulse to pulse. Many experiments that employ XFEL radiation require the resolution of the spectrum of each pulse. The work presented here investigates the capacity of a thin strongly bent diamond crystal to resolve the energy spectra of hard X-ray SASE pulses by studying its diffraction properties. Rocking curves of the symmetric C*(440) reflection have been measured for different bending radii. The experimental data match the theoretical modelling based on the Takagi–Taupin equations of dynamical diffraction. A uniform strain gradient has proven to be a valid model of strain deformations in the crystal.

scholarly journals Energy spectra of muonic atoms in quantum electrodynamics

2019 ◽  
Vol 204 ◽  
pp. 05007 ◽  
Author(s):  
A. E. Dorokhov ◽  
A. A. Krutov ◽  
A. P. Martynenko ◽  
F. A. Martynenko ◽  
O. S. Sukhorukova
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Energy Spectrum ◽  
Hyperfine Structure ◽  
Nuclear Structure ◽  
Quantum Electrodynamics ◽  
Vacuum Polarization ◽  
Energy Spectra ◽  
Hyperfine Splittings ◽  
S States

Vacuum polarization, nuclear structure and recoil, radiative corrections to the hyperfine structure of S-states in muonic ions of lithium, beryllium and boron are calculated on the basis of quasipotential method in quantum electrodynamics. We consider contributions in first and second orders of perturbation theory which have the order α5 and α6 in the energy spectrum. Total values of hyperfine splittings are obtained which can be used for a comparison with future experimental data.

Composition and spectra of primary cosmic-ray electrons and nuclei above 10 10 eV

1975 ◽  
Vol 277 (1270) ◽  
pp. 349-363 ◽  
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Energy Spectra ◽  
Average Lifetime ◽  
Interstellar Space ◽  
Interstellar Matter ◽  
Electromagnetic Interactions ◽  
Nuclear Species ◽  
The Galaxy ◽  
High Energy Particles

Recent experiments have extended the knowledge of the flux and energy spectra of individual cosmic-ray components to much higher energies than had previously been accessible. Both electron and nuclear components show a behaviour at high energy which is unexpected, and which carries information regarding the sources and the propagation of particles between sources and observer. Electromagnetic interactions which are suffered by the electrons in interstellar space should steepen their spectrum, a steepening that would reveal the average lifetime a cosmic-ray particle spends in the galaxy. Measurements up to 1000 GeV show no such steepening. It was discovered that the composition of the nuclear species which is now measured up to 100 GeV/nucleon changes with energy. This change indicates traversal of less interstellar matter by the high energy particles than by those of lower energy. We discuss the experimental evidence and its implication.

scholarly journals The Pierre Auger Observatory: Review of Latest Results and Perspectives

Universe ◽  
2018 ◽  
Vol 4 (11) ◽  
pp. 128 ◽  
Author(s):  
Dariusz Góra ◽  
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Detection System ◽  
Cosmic Ray ◽  
High Energy ◽  
Pierre Auger Observatory ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Energy Limitation ◽  
Arrival Directions

The Pierre Auger Observatory is the world’s largest operating detection system for the observation of ultra high energy cosmic rays (UHECRs), with energies above 10 17 eV. The detector allows detailed measurements of the energy spectrum, mass composition and arrival directions of primary cosmic rays in the energy range above 10 17 eV. The data collected at the Auger Observatory over the last decade show the suppression of the cosmic ray flux at energies above 4 × 10 19 eV. However, it is still unclear if this suppression is caused by the energy limitation of their sources or by the Greisen–Zatsepin–Kuzmin (GZK) cut-off. In such a case, UHECRs would interact with the microwave background (CMB), so that particles traveling long intergalactic distances could not have energies greater than 5 × 10 19 eV. The other puzzle is the origin of UHECRs. Some clues can be drawn from studying the distribution of their arrival directions. The recently observed dipole anisotropy has an orientation that indicates an extragalactic origin of UHECRs. The Auger surface detector array is also sensitive to showers due to ultra high energy neutrinos of all flavors and photons, and recent neutrino and photon limits provided by the Auger Observatory can constrain models of the cosmogenic neutrino production and exotic scenarios of the UHECRs origin, such as the decays of super heavy, non-standard-model particles. In this paper, the recent results on measurements of the energy spectrum, mass composition and arrival directions of cosmic rays, as well as future prospects are presented.

Aspects Of High Energy Astrophysics

1972 ◽  
Vol 2 (2) ◽  
pp. 70-71
Author(s):  
J. R. Prescott
Keyword(s):  
Cosmic Rays ◽  
High Energy ◽  
Electromagnetic Spectrum ◽  
High Energy Astrophysics ◽  
Observational Astronomy

Observational astronomy extends, in terms of energy in the electromagnetic spectrum, from below 10-8eV to above 108eV. Studies of cosmic rays extend this range to the neighbourhood of 1019eV (about a Joule) and the aspects of high energy astrophysics discussed in the present paper are those concerned with cosmic rays of energy upwards of about 1015eV.

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.

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