A FAST JFET-CMOS-SIMOX MONOLITHIC AMPLIFIER SYSTEM FOR THE E831 MICROVERTEX DETECTOR

A new monolithic front-end system was purposely developed for the read out of the silicon microstrip vertex detector of the E831 fixed target experiment at Fermilab. The chip, fabricated in a JFET-CMOS-SIMOX tec hnology, consists of 32 analog channels, performing signal preamplific ation and time-invariant shaping with 25 ns peaking time. The paper pr esents the results of the experimental characterisation of the chip, i ncluding an evaluation of the noise performances in the actual E831 re adout system, where the chip analog outputs are processed by a charge- sensing ADC, with a gated integrator acting as a time-variant shaper.