Author/Authors :
Adler، نويسنده , , R. and Backenstoss، نويسنده , , G. and Bal، نويسنده , , F. and Behnke، نويسنده , , O. and Bloch، نويسنده , , P. and Damianoglou، نويسنده , , D. and Dechelette، نويسنده , , P. and Drِge، نويسنده , , M. and Eckart، نويسنده , , B. and Felder، نويسنده , , C. and Fetscher، نويسنده , , W. and Fidecaro، نويسنده , , M. and Garreta، نويسنده , , D. and Gerber، نويسنده , , H.-J. and Gumplinger، نويسنده , , P. and Guyon، نويسنده , , D. ، نويسنده ,
Abstract :
A large-acceptance lead/gas sampling electromagnetic calorimeter (ECAL) was constructed for the CPLEAR experiment to detect photons from decays of π0s with momentum pπ0 ≤ 800 MeV/c. The main purpose of the ECAL is to determine the decay vertex of neutral-kaon decays K0 → π0π0 → 4γ and K0 → π0π0π0 → 6γ. This requires a position-sensitive photon detector with high spatial granularity in r−, ϕ−, and z−coordinates. The ECAL - a barrel without end-caps located inside a magnetic field of 0.44 T - consists of 18 identical concentric layers. Each layer of 13 radiation length (X0) contains a converter plate followed by small cross-section high-gain tubes of 2640 mm active length which are sandwiched by passive pick-up strip plates. The ECAL, with a total of 6X0 has an energy resolution of α(E)E ≈ 13%(E(GeV)and a position resolution of 4.5 mm for the shower foot. The shower topology allows separation of electrons from pions. The design, construction, read-out electronics, and performance of the detector are described.
