Dottorato in FISICA DEGLI ACCELERATORI

Titolo della tesi: Beam Dynamics of High Brightness Beams in RF Photoinjectors

Intense electron beams with high luminosity, such as those generated by radio-frequency (RF) photoinjectors, facilitate cutting-edge applications in the production of photons and the operation of high-energy physics colliders. Notable examples of advanced applications in these fields include Free Electron Lasers (FELs), Inverse Compton Scattering (ICS) sources, and high-luminosity linear electron-positron colliders. Such particle beams necessitate the simultaneous presence of high peak currents, minimal transverse emittance, and narrow energy spectra, resulting in a dense distribution in the six-dimensional phase space. Consequently, understanding the dynamics of these beams is a fundamental aspect of designing and generating high-quality beams. The research work presented in this manuscript investigates various approaches to understanding and improving the dynamics of beams generated by photoinjectors. In particular, we focus on beam dynamics in the context of the hybrid photoinjector, which combines traveling wave and standing wave structures in a single device. This study is based on simulation analysis and developing analytical models for emittance compensation. A different approach is centered on optimizing beam quality for experiments in the field of plasma acceleration within the SPARC_LAB collaboration. In this context, the work shown aims to enhance beam quality to exploit the potential of plasma acceleration fully. The results obtained from this study have led to experimental results presented in the manuscript. Furthermore, this work has been influenced by the experiences gained at the University of California, Los Angeles (UCLA), where experimental and theoretical activities were carried out in collaboration with the Particle Beam Physics Laboratory (PBPL). These experiences have further enriched my understanding of beam dynamics and advanced accelerator appli- cations, concluding my doctoral journey with the study of an entirely innovative dynamics that combines the two main areas addressed throughout the manuscript.