Author/Authors :
Shimizu، نويسنده , , H. and Miyahara، نويسنده , , F. and Hariu، نويسنده , , H. and Hayakawa، نويسنده , , T. and Ishikawa، نويسنده , , T. and Itaya، نويسنده , , M. and Iwata، نويسنده , , T. and Kinoshita، نويسنده , , T. and Moriya، نويسنده , , M. and Nakabayashi، نويسنده , , T. and Sasaki، نويسنده , , T. and Tajima، نويسنده , , Y. and Takita، نويسنده , , S. and Yamamoto، نويسنده , , M. and Yamazaki، نويسنده , , H. and Yoshida، نويسنده , , H.Y. ، نويسنده ,
Abstract :
A beam test has been performed on a prototype electromagnetic calorimeter of bismuth silicate BSO crystals for the first time using electrons of 0.5–3.0 GeV. The calorimeter consists of nine BSO crystals, 22 mm × 22 mm × 180 mm (15.6 radiation lengths), arranged in a 3 × 3 array. Each crystal is coupled to a small photomultiplier tube of 20 mm in diameter. The obtained energy resolution is σ E / E = ( 0.023 ± 0.003 ) / E ( GeV ) ⊕ ( 0.017 ± 0.002 ) for incident electrons of the energy E in GeV. The position information for an electron injected onto the center crystal of the calorimeter array is given with energy deposit signals from nine BSO crystals. The RMS position resolution σ x is parameterized as σ x = [ ( 3.2 ± 0.1 ) / E ( GeV ) ⊕ ( 1.3 ± 0.1 ) ] mm at the center of the crystal. Misidentification probability of pions to electrons is found to be ∼ 10 - 3 for the pion momentum ranging from 1.0 to 3.0 GeV/c.
