The Telescope Array Project

The Telescope Array project aims at understanding the origin of super-GZK cosmic rays, which is the most intriguing and urgent problem of the cosmic ray physics today. Addressing the problem may entail to understand the high energy astrophysical objects and the violent transient phenomena of the present universe, or the elementary particle reactions in the very early universe. The identification of the primary particle species, the search for the point source and the global anisotropy are important experimental features charged to the new generation cosmic ray detectors. The Telescope Array plans to deploy 10 large air fluorescence stations in the West desert of Utah covering the acceptance of 65,000 km2 sr with 10 % duty factor. It will be co-sited with the northern hemisphere Pierre Auger ground arrays of the similar exposure. The gamma ray primary will be identified with the modulation of the shower maximum; an elongation of the shower by the LPM effect and the north- south asymmetry by the geomagnetic cascade. A uniform detection of the air showers in the entire atmosphere will be Correspondence to: S. Ogio (sogio@cr.phys.titech.ac.jp) most suited for the identification of the horizontal showers produced by the neutrinos. With a stereo reconstruction, an angular resolution of 0.6° is expected for the 1020 eV shower.