The cosmic ray spectrum and composition measured by KASCADE-Grande between '10 POT. 16' eV and '10 POT. 18' eV

Abstract

The shape and composition of the primary spectrum of cosmic rays are key elements to understand the origin, acceleration and propagation of the Galactic cosmic rays. Besides the well known knee and ankle features, the recent results of KASCADE-Grande indicate that the measured energy spectrum exhibits also a less pronounced but still clear deviation from a single power law between the knee and the ankle, with a spectral hardening at 2 × '10 POT. 16' eV and a steepening at '10 POT. 17' eV. The average mass composition gets heavier after the knee till '10 POT. 17' eV where a bending of the heavy component is observed. An indication of a hardening of the light component just above '10 POT. 17' eV has been measured as well. In this paper the major results obtained so far by the KASCADE-Grande experiment are reviewed.