Front end electronics for the jet drift chamber

The Jet Drift Chamber employs a charge division readout scheme which requires two amplifiers per sense wire. Since there are 690 sense wires, 1380 amplifiers are needed. It follows that each end cap must accommodate 690 amplifiers which makes packaging and cooling critical problems. As a result, 30 six-layer surface mount boards each containing 24 (23 used) channels of amplifiers have been made. Each amplifier could accept up to 2 pC of charge and could provide a linear differential output of +- 300 mV which is used to drive a twisted pair transmission line up to 70' in length. The power dissipation of each board is 1.5 W