高速数字式TDC

High Speed Digital TDC for DO Vertex Reconstruction

本文介绍的高速TDC用来快速决定粒子流发生对撞的初步位置。粒子对撞时将产生大量新出射粒子。通过测定这些新粒子出射束到达零级触发器的时间,即可确定对撞的顶点位置,进而为Ⅰ级触发器提供计算粒子横向能量所需知的方向角加权因子sinθ。该TDC由全数字式GaAs集成电路组成,其时间分辨达到226 ps。

A high speed digital TDC has been built as part of the Level 0 trigger for the DO experiment at Fermilab.The digital TDC is used to make a fast determination of the primary vertex position by timing the arrival times of beam jets detected in the Level 0 counters.The vertex position is then used by the Level 1 trigger to determine the proper siu9 weightieg factors for calculating transverse energies.Commercial GaAs integrated circuits are used in the digital TDC to obtain a time resolution of Ot = 226 ps0