TheGAMMA experiment is a study of:
The GAMMA experiment is deployed on the South side ofMount Aragats inArmenia (Cosmic-ray observatory) and operated by the Cosmic Ray Division of theYerevan Physics Institute.[5][6] The facility consists of a ground-based extensiveair shower (EAS) array of 33 surface detection stations and 150 underground muon detectors. The elevation of the GAMMA facility is 3200 mabove sea level, which corresponds to about 700 g/cm2 of atmospheric depth. The surface stations of the EAS array are arranged in 5 concentric circles of 20, 28, 50, 70, and 100 m radii, and each station contains 3 plasticscintillation detectors with the dimensions of 1 m × 1 m × 0.05 m. 9 central detector stations contain an additional small scintillator with dimensions 0.3 m × 0.3 m × 0.05 m for high particle density (much greater than 100 particles/m2) measurements. Aphotomultiplier tube is placed on the top of the aluminum casing covering each scintillator. One of three detectors of each station is viewed by two photomultipliers, one of which is designed for fast timing measurements. 150 underground muon detectors are compactly arranged in the underground hall under 2.3 kg/cm2 of concrete and rock providing the detection of shower muons with energy greater than 5 GeV.
The results of GAMMA experiment for 2004–2010 runs are presented in references below.[7]