Owing to their ultra-high accelerating gradients, combined with injection inside micrometer-scale accelerating wakefield buckets, plasma-based accelerators hold great potential to drive a new generation of free-electron lasers (FELs). Indeed, the first demonstration of plasma-driven FEL gain was reported recently, representing a major milestone for the field. Several groups around the world are pursuing these novel light sources, with methodology varying in the use of wakefield driver (laser-driven or beam-driven), plasma structure, phase-space manipulation, beamline design, and undulator technology, among others. This paper presents our best attempt to provide a comprehensive overview of the global community efforts towards plasma-based FEL research and development.

Laser matter interaction in the regime of super-intense and ultra-short laser pulses is discovering common interests and goals for plasma and elementary particles physics. Among them, the electron laser wakefield acceleration and the X/γ tunable sources, based on the Thomson scattering (TS) of optical photons on accelerated electrons, represent the most challenging applications. The activity of the Intense Laser Irradiation Laboratory in this field will be presented.

The results from theoretical and experimental studies, as well as from 2.5-dimensional (2.5-D) numerical simulation of plasma wake field excitation, by either relativistic electron bunch, laser pulse, and the charged particle wake field acceleration are discussed. The results of these investigations make it possible to evaluate the potentialities of the wake field acceleration method and to analyze whether it can serve as a basis for creating a new generation of devices capable of charged particle accelerating at substantially higher (on the order of two to three magnitudes) rates in comparison with those achievable in classical linear high-frequency (resonant) accelerators.

High-amplitude plasma wake waves are excited by high-density relativistic electron bunches (REB) moving in a plasma. The wake-fields can be used to accelerate charged particles, to serve as electrostatic wigglers in plasma free-electron lasers (FEL), and also can find many other applications. The electromagnetic fields in the region occupied by the bunch control the dynamics of the bunch itself. This paper presents the results of 2.5-dimensional numerical simulation of the modulation of a long REB in a plasma, the excitation of wake-fields by bunches in a plasma, in particular, in magnetoactive plasma. The previous one-dimensional study has shown that the density-profile modulation of a long bunch moving in plasma results in the growth of the coherent wake-wave amplitude. The bunch modulation occurs at the plasma frequency. The present study is concerned with the REB motion, taking into account the plasma and REB nonlinearities. It is demonstrated that the nonlinear REB/plasma dynamics exerts primary effect on both the REB self-modulation and the wake-field excitation by the bunches formed. We have demonstrated that a multiple excess of the accelerated bunch energy εmax over the energy of the exciting REB is possible in a magnetoactive plasma for a certain relationship between the parameters of the “plasma–bunch–magnetic field” system (owing to a hybrid volume–surface character of REB-excited wake-fields).