Shashlik calorimeter: Beam test results

Abstract Results from an extensive study of nonprojective Shashlik calorimeter prototypes are reported. Nine (47 × 47 mm 2 ) towers were exposed to a high energy electron beam at CERN SPS and read out by silicon photodiodes followed by low noise preamplifiers. The main results are the measurements of the energy and shower position resolution and the angular resolution of the electron shower direction. The shower direction measurement is encouraging being in agreement at the tower center with a resolution of σ θ (mrad) = 70/√ E (10 mrad for 50 GeV electrons). The uniformity of the calorimeter response is found to be better than ± 1%. The mean light yield measured in Shashlik towers equipped with Kuraray Y7 WLS fibres and aluminized at the front end of the tower is of the order of 13 photons/MeV.