Département d'Ingénierie des Systèmes

This doctoral dissertation investigates the potential of Micro-Pattern Gaseous Detectors for High Energy Physics and beyond, focusing on time resolution and optical readout advancements. 

The primary aim was the PICOSEC Micromegas project, concentrating on developing precise-timing gaseous detectors with a target time resolution of O(10) ps for Minimum Ionising Particles. This dissertation focused on enhancing performance and scaling it to robust multi-channel detector modules. Research on photocathode materials showed that Diamond-Like Carbon was the most promising due to its good timing properties and resistance to humidity. The integration of resistive Micromegas aimed to improve robustness against discharges and ensure stable operation under intense particle beams, achieving a record time resolution of σ ≈ 12.5 ps. Finally, multi-channel prototypes were developed to scale to larger detection areas, achieving a time resolution below σ = 18 ps for a 10×10 cm2 module.

Additionally, this doctoral dissertation explores the potential benefits of optical readout techniques for MPGDs and aims to enhance their performance. The research includes an evaluation of spatial resolution through optical readout, comparing different detector geometries. It investigates various GEM-stack configurations to improve the dynamic range for future modifications of the MIGDAL OTPC, evaluating the maximum achievable gain and light yield across different GEM-based structures.  It also recognises the importance of reducing greenhouse gas emissions in gaseous detector by exploring alternative gases to CF4 and wavelength shifters for optical readout.