A Simulation to Seach for Gamma-ray Sources by Using Water Cherenkov Detector at the Tibet Altitude

中西 高明


   Optimization and verification are performance for a water Cherenkov detector at high altitude of 4300 m a.s.l. by two simulation codes of Cosmos and GEANT which use the Monte Carlo method. The detector consists of a water pool with an area of 50m X 50m and a depth of 1.5 m. Photomultiplier tubes are arranged in the pool with a 17 X 17 matrix pattern with a spacing of 3m, therefore, their total number are 289.
   As a result, angular resolution of the detector is obtained to be about 0.7 degree for a primary energy of 1 TeV. Trigger rate is expected to be larger than 15 kHz. Significance for gamma sources is obtained to be about 30σ for gamma-ray burst of GRB910503 and about 5σ for the Crab nebula with an observation of 30 days.