Fundamentals and Applications of Hybrid LWFA-PWFA

International audienceFundamental similarities and differences between laser-driven plasma wakefield acceleration (LWFA) Plasma Wakefield Acceleration (PWFA) and particle-driven plasma wakefield acceleration (PWFA) Plasma Wakefield Acceleration (PWFA) are discussed. The complementary features enable the conception and development of novel hybrid plasma acceleratorsLaser-plasma accelerator, which allow previously not accessible compact solutions for high quality electron bunchElectron bunch generation and arising applications. Very high energy gains can be realized by electron beam drivers even in single stages because PWFA is practically dephasing-free and not diffraction-limited. These electron driver beams for PWFA in turn can be produced in compact LWFA stages. In various hybrid approaches, these PWFA systems can be spiked with ionizing laser pulses to realize tunable and high-quality electron sources via optical density downramp injectionDownramp injection (also known as plasma torch) Plasma torch or plasma photocathodesPlasma photocathode (also known as Trojan Horse) and via wakefield-induced injection (also known as WII). These hybrids can act as beam energy, brightness and quality transformers, and partially have built-in stabilizing features. They thus offer compact pathways towards beams with unprecedented emittanceEmittance and brightness, which may have transformative impact for light sources and photon science applications. Furthermore, they allow the study of PWFA-specific challenges in compact setups in addition to large linac-based facilities, such as fundamental beam–plasma interaction physics, to develop novel diagnostics, and to develop contributions such as ultralow emittanceEmittance test beams or other building blocks and schemes which support futurePlasma-based collider plasma-based collider concepts