Author/Authors :
Tameda، نويسنده , , Yuichiro and Taketa، نويسنده , , Akimichi and Smith، نويسنده , , Jeremy D. and Tanaka، نويسنده , , Manobu and Fukushima، نويسنده , , Masaki and Jui، نويسنده , , Charles C.H. and Kadota، نويسنده , , Ken’ichi and Kakimoto، نويسنده , , Fumio and Matsuda، نويسنده , , Takeshi and Matthews، نويسنده , , John N. and Ogio، نويسنده , , Shoichi and Sagawa، نويسنده , , Hiroyuki and Sakurai، نويسنده , , Nobuyuki and Shibata، نويسنده , , Tatsunobu and Takeda، نويسنده , , Masahiro and Thomas، نويسنده , , Stanton B. and Tokuno، نويسنده , , Hisao and Tsunesada، نويسنده , , Yoshiki and Udo، نويسنده , , Shigeharu، نويسنده ,
Abstract :
The Telescope Array Project is an experiment designed to observe Ultra High Energy Cosmic Rays via a “hybrid” detection technique utilizing both fluorescence light detectors (FDs) and scintillator surface particle detectors (SDs). We have installed three FD stations and 507 SDs in the Utah desert, and initiated observations from March 2008. The northern FD station reuses 14 telescopes from the High Resolution Flyʹs Eye, HiRes-I station. Each of the two southern FD stations contains 12 new telescopes utilizing new FADC electronics. Each telescope is instrumented with a camera composed of 256 PMTs. Since the detectors are composed of many PMTs and each PMT detects fluorescence photons together with the vast amount of night sky background, a sophisticated triggering system is required. In this paper, we describe the trigger electronics of these new FD stations. We also discuss performance of the FDs with this triggering system, in terms of efficiencies and apertures for various detector configurations.
Keywords :
Monte Carlo technique , Ultra high energy cosmic rays , Extensive Air Shower , Fluorescence light , Event trigger
