Author/Authors :
Braem، نويسنده , , A. and Chesi، نويسنده , , E. and Dulinski، نويسنده , , W. and Filthaut، نويسنده , , Alan F. and Go، نويسنده , , A. and Joram، نويسنده , , C. and Lion، نويسنده , , G. and Seguinot، نويسنده , , J. and Weilhammer، نويسنده , , P. and Wicht، نويسنده , , P. and Ypsilantis، نويسنده , , T.، نويسنده ,
Abstract :
The LHCb experiment is being designed to study CP violation in the B meson sector. It differs from other LHC experiments in its excellent particle identification capability. This is accomplished by two focused RICH counters: RICH 1 has 5 cm thick aerogel and 95 cm long C4F10 radiators while RICH 2 uses 180 cm long CF4 radiator. The combined system will give π/K separation in the momentum range 1–150 GeV/c. Spherical mirrors are used to focus the Cherenkov light on detection planes equipped with photodetectors. One photodetector option is the large-area Hybrid Photodiode (HPD). An HPD consists of a cylindrical vacuum envelope of 127 mm diameter capped with a spherical borosilicate glass entrance window. Electrodes demagnify the image onto a silicon sensor comprising 2048 pads, each with a surface of 1 mm2. A large UHV evaporation plant for the production of HPDs with visible light bialkali photocathodes (K2CsSb) has been built and successfully operated producing photocathodes with good quantum efficiency and stability. A Cold Indium sealing technique has been developed and proven to provide excellent vacuum tightness.
