FI_KLFF18: Laser wakefield acceleration: diagnostics and applications

Laser wakefield acceleration (LWFA) differs from the conventional radio-frequency sources since the accelerating cavity is re-created at every laser shot by the interaction of an ultra-intense laser pulse with an underdense plasma. At ELI-Beamlines, we have two in-house world-leading LWFA machines: ELBA and ALFA. ELBA is the first worldwide high repetition rate laser-electron collider working at parameters enabling fundamental studies on the dynamics of energetic particles in strong electromagnetic fields and potentially revealing more insights on the nature of the quantum vacuum. ELBA electron accelerator has been commissioned in September 2023, and it is planned to fully commission the laser-electron collider in the first half of 2026. ALFA is the first worldwide kHz LWFA machine providing electron beams with energy up to 50 MeV. ALFA is open for experiments since 2023, and targets communities working on LWFA applications, such as light sources, radiotherapy, medical imaging and space. While being the most compact technology to produce ultra-relativistic electron beams, LWFA creates also strong electro-magnetic pulses and is accompanied by a broadband x-ray emission, creating a complex environment for diagnostics. For this reason, our team is pioneering several new methods to monitor the online performance of our in-house electron accelerators ELBA and ALFA. This thesis will advance the state of the art of LWFA diagnostics. Moreover, it will expand the spectrum of LWFA applications.