Deployment of the readout electronics for the BESIII Cylindrical GEM Inner Tracker

Abstract

The Beijing Spectrometer (BESIII) is an experimental setup located at the Beijing Electron Positron Collider (BEPCII). The recently approved ten-year extension of data acquisition for BESIII prompted an upgrade program for both the BEPCII collider that houses the experiment and some of the sub-detectors that make up the spectrometer. The current inner drift chamber is suffering from aging and it has been proposed to replace it with a detector based on the Cylindrical Gas Electron Multiplier (CGEM) technology. The CGEM Inner Tracker (CGEM-IT) consists of three coaxial layers of triple GEM. The lightweight tracker is designed to recover efficiency and improve z-determination and secondary vertex position reconstruction, resulting in a better performance and longer lifetime. A novel system has been deeloped for the readout of the CGEM detector, including a new ASIC, called TIGER (Torino Integrated GEM Electronics for Readout), designed to amplify and digitize the CGEM signals. The data output from TIGER are collected and processed by a first FPGA-based module, GEM Read Out Card, which is responsible for configuring and controlling the front-end ASICs. A second FPGA-based module, GEM Data Concentrator (GEM DC), builds the event packets and transmits them to the BESIII data acquisition system. In this thesis I will describe the entire custom electronics chain designed for the CGEM-IT to achieve the desired performance. The structure of my work is presented along with the results of the measurements performed on the detector and the analysis of the data obtained with the detection of cosmic rays and under test beam.