The Design and Performance of the ZEUS Central Tracking Detector z-by-Timing System

TL;DR

The paper presents the design and performance evaluation of the ZEUS Central Tracking Detector's z-by-timing system, which uses precise time measurements for accurate 3D tracking in high-energy physics experiments.

Contribution

It introduces a novel z-by-timing measurement technique with a high-resolution TDC, automated calibration, and integrated data acquisition for improved 3D tracking in ZEUS.

Findings

Achieved a z-resolution of 4.4 cm for multi-track events.

Implemented a synchronized timing control system with the HERA beam-crossing clock.

Demonstrated effective use of z-by-timing data in trigger and offline reconstruction.

Abstract

The ZEUS Central Tracking Detector utilizes a time difference measurement to provide a fast determination of the z-coordinate of each hit. The z-by-timing measurement is achieved by using a Time-to-Amplitude Converter which has an intrinsic timing resolution of 36 ps, has pipelined readout, and has a multihit capability of 48 ns. In order to maintain the required sub-nanosecond timing accuracy, the technique incorporates an automated self-calibration system. The readout of the z-by-timing data utilizes a fully customized timing control system which runs synchronously with the HERA beam-crossing clock, and a data acquisition system implemented on a network of Transputers. Three dimensional space-points provided by the z-by-timing system are used as input to all three levels of the ZEUS trigger and for offline track reconstruction. The average z-resolution is determined to be 4.4 cm for multi-track events from positron-proton collisions in the ZEUS detector.