Changes of the cosmic-ray mass composition in the 10^{14} - 10^{16} eV energy range
Abstract
Changes of the cosmic-ray mass composition at the `knee' of the cosmic-ray flux spectrum near 10^{15} eV energy are investigated using data from ten Cosmic Ray Tracking (CRT) detectors and the HEGRA air-shower array on La Palma, Canary Islands. The analysis is based on the angular distribution of muons in air showers. Results can be easily expressed in terms of <ln A> of primary cosmic rays. We find a rise of <ln A> below 10^{15} eV, consistent with direct measurements. Simple cosmic-ray composition models are presented which are fully consistent with our results as well as the JACEE flux and composition measurements and the flux measurements of the Tibet AS-gamma collaboration.
Keywords
Cite
@article{arxiv.astro-ph/9801042,
title = {Changes of the cosmic-ray mass composition in the 10^{14} - 10^{16} eV energy range},
author = {K. Bernlohr and W. Hofmann and G. Leffers and V. Matheis and M. Panter and R. Zink},
journal= {arXiv preprint arXiv:astro-ph/9801042},
year = {2009}
}
Comments
22 pages, 11 Postscript figures, 2 tables. Accepted for publication in Astroparticle Physics