Introduction

Petawatt and exawatt class lasers worldwide

“…FELs are unique X-ray light sources with unprecedented peak brightness, offering insights into matter, molecules, chemistry, biology and so forth, otherwise not accessible. Shrinking the electron accelerator (typically a few tens of GeV) from several kilometres down to a laser-driven plasma accelerator that occupies only a few metres in real estate would allow a dramatic cost reduction and enlarging the user base of these unique light sources [45–47] .…”

“…The system performance is planned to be 3 J at 1 kHz operating at 30 fs. So, although not necessarily within the scope of the review in terms of power (100 TW) this is an important system which will be a technology demonstrator for much higher power systems [47] .…”

“…Born from the integration of a high-brightness photo-injector (SPARC) and of a high-power laser (FLAME); SPARC_LAB is mainly devoted to conducting further development, characterization and application of compact radiation sources (FEL, THz, Compton) driven by plasma-based accelerator modules. This will investigate the techniques of: LWFA (laser wakefield acceleration), which uses short-pulse laser drivers to excite the wake; and PWFA (plasma wakefield acceleration), which uses a high-energy particle bunch to excite the wake [47] .The Intense Laser Irradiation Laboratory (ILIL), CNR (Consiglio Nazionale delle Ricerche) National Institute of Optics, Pisa was established in 2001 following more than a decade of experimental activity in the field of high-power laser–plasma interaction, also as a founding member of European collaboration programmes in the field, pioneering access to large-scale facilities and hosting Training Network activities. Today the laboratory is an active member of the Italian Extreme Light Infrastructure initiative and a partner of the EuPRAXIA H2020 collaboration (see 2.2.8) and is also an associate partner of the Eurofusion consortium.…”

“…Born from the integration of a high-brightness photo-injector (SPARC) and of a high-power laser (FLAME); SPARC_LAB is mainly devoted to conducting further development, characterization and application of compact radiation sources (FEL, THz, Compton) driven by plasma-based accelerator modules. This will investigate the techniques of: LWFA (laser wakefield acceleration), which uses short-pulse laser drivers to excite the wake; and PWFA (plasma wakefield acceleration), which uses a high-energy particle bunch to excite the wake [47] .…”

“…Facilities, currently in their final commissioning phase, like the European Extreme Light Infrastructure (ELI) pillars in the Czech Republic, Romania and Hungary [45] , are pushing forward this concept, providing user access not only to laser beamlines, but also to laser-produced secondary radiation and particle sources, including gamma-ray, proton and electron beams. Facilities currently in their conceptual development phase, like the European EuPRAXIA infrastructure [46] or the US k-BELLA facility [47] , aim at further advancing this concept, by incorporating step-like changes in the design to enable high-repetition-rate, accelerator-like, high-quality operation of the secondary sources, in a compact size and efficient mode of operation. In light of these developments, the later sections of the review therefore address three areas: ultra-high-power development; high-average-power development; and enabling technologies.…”