In principle, there are several methods to create the high-quality multi-GeV electron beams by plasma acceleration proposed for EuPRAXIA. In the first place, the plasma wakefield can be driven by a high-power laser pulse (Laser Wakefield Acceleration – LWFA) or by a moderate energy electron beam (Plasma Wakefield Acceleration – PWFA). The first technique requires a laser system able to deliver pulses of around 100 fs duration in the petawatt regime; the second employs either a radiofrequency (RF) electron linac or a laser wakefield accelerator providing 0.5 – 1.0 GeV electrons in ultrashort bunches of a few femtoseconds.

Secondly, the accelerated particle beam may come from the plasma electrons trapped in the back of the wake (internal injection) or from an external electron beam, precisely timed to arrive at the plasma structure on the peak of the longitudinal electric field in the forward direction (external injection). The external electron beam, in turn, may come from a radiofrequency linac or a preceding laser wakefield accelerator.

Finally, the electrons may be accelerated up to the final energy in a single plasma structure or in a sequence of plasma structures where the electrons accelerated in the first stage are injected in a second stage for further acceleration.


The EuPRAXIA study is considering all possible combinations between these schemes at the moment, in order to reach its baseline parameters. In total, there are nine different scenarios, of which the most promising ones will be selected in 2019:

Preliminary study concept 

The power sources will be designed around the established requirements for driving the accelerating plasma structures and the electron beam injection.

The EuPRAXIA Facility

Facility structure

The baseline parameters for the electron beam output are defined by the main applications of EuPRAXIA: free-electron lasers (FEL), high-energy physics detector applications (HEP), and other pilot applications (Other).

Power sources

The EuPRAXIA facility can be divided into three main sections:

1) Power sources (RF electron linacs and high-power laser systems)

2) Accelerator machine, consisting of

• Plasma structures,

• Transport lines to carry the electron beams from the injectors to the plasma structures and to the experimental areas,

• Instrumentation to monitor and control the characteristics of the electron beams.

3) Experimental areas

• Free-electron lasers (FEL)

• High-energy physics (HEP) and other pilot applications

The total footprint of the facility, including power sources, plasma accelerator and the experimental areas for applications, is 250 m.

Output parameters