Design and development of the Level-1 Data Driver Card (L1DDC) for the New Small Wheel upgrade of the ATLAS experiment at CERN

ATLAS is one of the four main experiments located in the Large Hardon Collider at CERN. During Long Shutdown 2 (2019-2020) the innermost muon stations of ATLAS called the Small Wheels will be replaced by the New Small Wheel upgrade project. This upgrade is motivated by the high particle flux (up to 15 kHz/cm2), the high radiation during Run-3 (2021-2023) and ultimate luminosity of 7.5 × 10^(34) cm^(-2) s^-1 expected in High-Luminosity Large Hadron Collider (after 2026). The number of interactions per bunch-crossing (every 25 ns) will be increased upto 140, resulting in a dramatically large amount of produced data. The New Small Wheel is a set of precision tracking and trigger detectors able to work at high rates with excellent real-time spatial and time resolution. The new detectors consist of the resistive Micromegas and the small-strip Thin Gap Chambers. Furthermore, a radiation dose up to 1700 Gy (innermost radius) and a magnetic field up to 0.4 T in the end cap region, create a hostile environment for the front-end electronics. To read out the large number of electronic channels (~2.1 million for the Micromegas and ∼332 thousand for the sTGC) and in order to survive in such a harsh envi- ronment new electronics must be fabricated and installed. In addition, correction mechanisms for Single Event Upsets (this is a change of state caused by a high-energy particle strike to a micro-electronic device) must be implemented to assure the integrity of the transmitted data. The whole readout and trigger architecture of the NSW was redesigned including the fabrication of new electronic boards and Application Specific Integrated Circuits compatible even with the Run-4 data rates. The aim of this dissertation was the research and development of the Level-1 Data Driver Card which is part of the data acquisition system for both detector technologies and consists of radiation tolerant components. The development of the cards included a series of prototypes and their extensive testing independently, and as part of the final system as well. A major and extensive study to make these cards compatible even with the future (and demanding) upgrades of the experiment was performed. Up to now, eight different versions of these cards have been manufactured and tested. The latest prototypes, after their debugging, are the reference cards for mass production of 1056 Level-1 Data Driver Cards. Additionally for the needs of the experiment and for a more complete control and testing of the cards and the final system, a series of Front-Ends, a Low Voltage distributor and a series of auxiliary cards were designed and fabricated. Furthermore for the testing procedure of the boards different pieces of firmware were de- veloped using the Very High Speed Integrated Circuit Hardware Description Language. This development includes communication of the control system with the Level-1 Data Driver Card through optical link, the programming of the Application Specific Integrated Circuits on the Level-1 Data Driver Card card, the acquisition of environmental variables (voltage levels and temperatures) and their evaluation by a personal computer through the Ethernet interface and UDP/IP protocols. In order to validate the final system, a low-level code was also developed, tested and debugged to configure the Venetis MicroMegas Application Specific Integrated Cir- cuit (on the Front-Ends) to collect data from the detectors and transfer them via the UDP/IP protocol to a computer for storage and subsequent evaluation.