The cosmic ray composition between 1014 and 1016 eV

doi:10.1016/S0927-6505(99)00076-6

Elsevier

Astroparticle Physics

Volume 12, Issues 1–2, October 1999, Pages 1-17

Astroparticle Physics

https://doi.org/10.1016/S0927-6505(99)00076-6 Get rights and content

Abstract

The mass composition of cosmic rays with primary energies between 10¹⁴ eV and 10¹⁶ eV has been studied using the surface and buried scintillators of the CASA-MIA air shower array. Near 10¹⁴ eV, the composition of cosmic rays is in agreement with direct measurements, roughly half light elements (protons and helium) and half heavier elements. The average mass increases with energy, becoming heavier above 10¹⁵ eV. The mass changes coincide with the spectral steepening of the energy spectrum known as the knee. There is evidence for rigidity dependence in the spectral change. A method of calculating the primary cosmic ray energy which is insensitive to the composition is employed to achieve these results.

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Citation Excerpt :
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¹: Current address: Dept. of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA.

²: Joint appointment with The Adler Planetarium and Astronomy Museum, Astronomy Department, Chicago, Illinois 60605, USA.

³: Current address: Koch Industries, Wichita, KS 67201, USA.

⁴: Current address: Dept. of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 and Dept. of Physics, Southern University, Baton Rouge, LA 70801, USA.

⁵: Current address: Micro Encoder, Inc., Kirkland, WA 98034, USA.

⁶: Current address: Dept. of Physics, Michigan Technological University, Houghton, MI 49931, USA.

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Astroparticle Physics

The cosmic ray composition between 1014 and 1016 eV

Abstract

Nucl. Instrum. Meth. A

Astropart. Phys.

Astron. Astrophys.

Phys. Rev. Lett.

Phys. Rev. D

Ap. J.

J. Phys. G

Ann. Rev. Nucl. Sci

Progress in Elementary Particle and Cosmic Ray Physics III

Cosmic rays from the knee to the highest energies

KASCADE measurements of energy spectra for elemental groups of cosmic rays: Results and open problems

A Heitler model of extensive air showers

On the knee in the energy spectrum of cosmic rays

Cosmic rays and particle physics

Cosmic ray energy spectrum from measurements of air showers

The cosmic ray composition between 10¹⁴ and 10¹⁶ eV