Ankle-like feature in the energy spectrum of light elements of cosmic rays observed with KASCADE-Grande

Recent results of the KASCADE-Grande experiment provided evidence for a mild knee-like structure in the all-particle spectrum of cosmic rays at E = 10(16.92 +/- 0.10) eV, which was found to be due to a steepening in the flux of heavy primary particles. The spectrum of the combined components of light and intermediate masses was found to be compatible with a single power law in the energy range from 10(16.3) to 10(18) eV. In this paper, we present an update of this analysis by using data with increased statistics, originating both from a larger data set including more recent measurements and by using a larger fiducial area. In addition, optimized selection criteria for enhancing light primaries are applied. We find a spectral feature for light elements, namely, a hardening at E = 10(17.08 +/- 0.08) eV with a change of the power law index from -3.25 +/- 0.05 to -2.79 +/- 0.08. DOI: 10.1103/PhysRevD.87.081101