The DIRC front-end electronics chain for BaBar

The detector of Internally Reflected Cherenkov light (DIRC) of the BaBar de tector (SLAC Stanford, USA) measures better than 1 ns the arrival time of C herenkov photoelectrons, detected in a 11 000 phototubes array and their am plitude spectra. It mainly comprises of 64-channel DIRC Front-End Boards (D FB) equipped with eight full-custom Analog chips performing zero-cross disc rimination with 2 mV threshold and pulse shaping, four full-custom Digital TDC chips for timing measurements with 500 ps binning and a readout logic s electing hits in the trigger window, and DIRC Crate Controller cards (DCC) serializing the data collected from up to 16 DFBs onto a 1.2 Gb/s optical l ink. Extensive test of the pre-production chips have been performed as well as system tests. (C) 1999 Elsevier Science B.V. All rights reserved.