Measurements of the Cosmic Ray Composition with Air Shower Experiments

In this paper we review air shower data related to the mass composition of cosmic rays above 10$^{15}$ eV. After explaining the basic relations between air shower observables and the primary mass and energy of cosmic rays, we present different approaches and results of composition studies with surface detectors. Furthermore, we discuss measurements of the longitudinal development of air showers from non-imaging Cherenkov detectors and fluorescence telescopes. The interpretation of these experimental results in terms of primary mass is highly susceptible to the theoretical uncertainties of hadronic interactions in air showers. We nevertheless attempt to calculate the logarithmic mass from the data using different hadronic interaction models and to study its energy dependence from 10$^{15}$ to 10$^{20}$ eV.Comment: 21 pages, invited review accepted for publication in Astroparticle Physics, Topical Issue on Cosmic Ray

The Tunka-133 EAS Cherenkov light array: status of 2011

A new EAS Cherenkov light array, Tunka-133, with ~1 km^2 geometrical area has been installed at the Tunka Valley (50 km from Lake Baikal) in 2009. The array permits a detailed study of cosmic ray energy spectrum and mass composition in the energy range 10^16 - 10^18 eV with a uniform method. We describe the array construction, DAQ and methods of the array calibration.The method of energy reconstruction and absolute calibration of measurements are discussed. The analysis of spatial and time structure of EAS Cherenkov light allows to estimate the depth of the EAS maximum X_max. The results on the all particles energy spectrum and the mean depth of the EAS maximum X_max vs. primary energy derived from the data of two winter seasons (2009 -- 2011), are presented. Preliminary results of joint operation of the Cherenkov array with antennas for detection of EAS radio signals are shown. Plans for future upgrades -- deployment of remote clusters, radioantennas and a scintillator detector network and a prototype of the HiSCORE gamma-telescope -- are discussed.Comment: 8 pages, Proceedings of the RICAP 2011 Conference, submitted to NIM

Primary CR energy spectrum and mass composition by the data of Tunka-133 array

The Cherenkov light array for the registration of extensive air showers (EAS) Tunka-133 collected data during 5 winter seasons from 2009 to 2014. The differential energy spectrum of all particles and the dependence of the average maximum depth on the energy in the range of 6 ⋅ 1015–1018 eV measured for 1540 hours of observation are presented

The Tunka - Multi-component EAS detector for high energy cosmic ray studies

The EAS Cherenkov array Tunka-133, with about 3 km2 sensitive area, has been installed in the Tunka Valley, Siberia. The accessible energy range is 1015-1018 eV. In this contribution, a description of the array and main results obtained so far are presented. A current update of the array includes the deployment of scintillation stations, radio antennas, as well as optical stations. The deployments of these optical stations are the first step towards Tunka-HiSCORE, a wide-angle, large field-of-view gamma-ray telescope. © 2013 Elsevier B.V.S.F. Berezhnev...G.P. Rowell...et al