Readout electronics subgroup

In this paper, review of the readout electronics for the central tracking chamber at TRISTAN is described. The scale estimation for several models of the tracking chambers is also presented. There are two types of the preamplifier for the analog readout of sensing wire signals. One of them is a current sensitive type, and the other type is a charge sensitive type, which provides good S/N ratio. The pre-amplifier should be mounted directly on the chamber in order to reduce input capacitors. The time resolution must be good so as to meet a final position resolution of the chamber. Three types of time digitizer circuits (TDC) are considered. Those are the direct scaling of clock pulses, time expansion scheme, and time to analog conversion method. The analog digitizers are necessary to make dE/dx measurement, charge division to get Z coordinate, and to measure accurate position along the anode wires. Sensing wires are used for both dE/dx measurement and charge division readout. Three types of chambers, ie., JET chamber, time projection chamber and longitudinal drift chamber, are considered for scale estimation. The FASTBUS system is imposed in the system construction. The size of the data from the central tracking chamber is one of the basic parameters for designing the data acquisition system, and it was estimated. (Kato, T.)