HiSCORE - The Hundred*i square-km cosmic ORigin explorer.

Addressing the mysteries of cosmic rays requires a comprehensive observational approach, including information on mass composition and spectrum (from CR nuclei) as well as directional information (gamma-rays or neutrinos). HiSCORE covers both approaches using indirect air-shower observations of cosmic rays from 100 TeV to 1 EeV and gamma-rays in the so far poorly covered energy range from 10 TeV to several PeV. Among other questions of astroparticle and particle physics, HiSCORE will allow cosmic ray composition and spectral measurements in the transition range between Galactic and Extragalactic origin. Searching for gamma-rays from the PeV-accelerators, the pevatrons, will consititute a crucial building-block for solving the question of the origin of Galactic cosmic rays. HiSCORE is an array of non-imaging light-collecting stations for Cherenkov light-front sampling. The lateral Cherenkov photon density and arrival-time distribution are measured, allowing the reconstruction of the direction, the energy, and the particle type (mainly shower depth) of the primary particle. A prototype detector station was developed and first air-shower measurements were performed in the Tunka valley (Siberia). The deployment of an engineering array of up to 1 square-km is planned on the Tunka cosmic ray experiment site in Siberia for 2012/2013. [ABSTRACT FROM AUTHOR]