The cosmic ray energy spectrum in the range 1016 -- 1018 eV measured by KASCADE-Grande.

The KASCADE-Grande experiment, located at Campus North of the Karlsruhe Institute of Technology (Germany) is a multi-component extensive air-shower experiment devoted to the study of cosmic rays and their interactions at primary energies 10¹⁴ - 10¹⁸eV. One of the main goals of the experiment is the measurement of the all particle energy spectrum in the 10¹⁶ - 10¹⁸ eV range, i.e. extending the range accessible by KASCADE alone. The Grande detector samples the charged component (N_ch) of the air shower while the original KASCADE array provides in addition a measurement of the muon component (N_u). The combined information of N_ch and N_u is used to estimate the energy on an event-by-event basis and to derive the all-particle energy spectrum. Since the calibration of the observables in terms of the primary energy depends on Monte Carlo simulations, three different methods with partially different sources of uncertainties, have been considered and compared to each other to derive the systematics on the energy spectrum. The different methods employed to derive the spectrum and their uncertainties, as well as the implications of the obtained result, are discussed in detail. [ABSTRACT FROM AUTHOR]