Design of the readout electronics system for the STAR sTGC detector

This paper presents a readout electronics system for the STAR sTGC detector, which will be used in the STAR forward tracking system. In the STAR forward upgrade, the sTGC detector is a key subsystem to improve the forward rapidity (2.5 < η < 4.5) detection capability of STAR. The STAR sTGC detector, which consists of 20,000 channels, is required to have a good position resolution (< 200 μm) and a high tracking efficiency (> 95%). To measure the signals of all channels, we developed the STAR sTGC Readout Electronics System (STAR TRES). It consists of 96 front-end electronics boards (FEB) and 16 readout driver boards (ROD). The FEB, installed on the STAR sTGC detector, is designed to measure signals from the detector, while the ROD is designed to collect events data from FEBs and communicate with the STAR electronics system. The events data is transmitted from the FEB to the ROD at a rate of 3.2 Gbps, while the ROD communicates with the STAR electronics system at 10 Gbps. The prototype system of the STAR TRES was tested in a cosmic ray experiment, and the test results show that the STAR TRES meets all requirements of the STAR sTGC detector. The STAR TRES will finally be installed at BNL in September 2021. The specific characteristics and implementations are described in detail.