The main goal of this Research Activity is to develop a laser-accelerated, versatile electron and proton/ion source emitting in an unprecedented energy range. These advanced, high-energy particle beams with the concomitant environment (diagnostics, radiation protection, etc.) will allow accomplishing multidisciplinary societal applications. In particular, this Research Activity can provide a major contribution for the development of future high-quality and low-cost proton sources for cancer therapy.

Research Activity Description

The ELI facility is supposed to be built as central laser facility with different experimental stations that can be used and accessed independently by various communities to best develop and use new particle and photon beams for scientific progress, but also to transfer the corresponding knowledge to industrial and societal applications.

ELI will probably be the first facility providing beam time for pump-probe experiments using moderately relativistic ultra-short ion beams and synchronized high-intensity lasers, electron beams, X-ray sources or attosecond sources. What makes ELI additionally unique is the ability to vary all these different secondary sources independently as allowed by having independent individual driving laser beams and adapting them optimal to the requirement of the specific experiment.

The envisioned laser driven electron and proton/ion sources with huge energies (up to the GeV level), in combination with other high-energy particle and radiation sources, requires a specific environment close to that of conventional accelerators. In contrast to the latter, which are planned for a dedicated energy range, the laser driven source is, according to the laser parameters that will be available on ELI and the projected parameters of the produced source, a “broadband” facility, which has to fulfill at least two aspects: first, to explore the optimum mechanisms to create efficiently highest energy and flux accompanied by shaping the energy spectra with the available laser parameters, and second, to use them for the envisioned scientific program and different other applications.

In recent years the dramatic rise in attainable laser intensity has generated an even more dramatic emergence and now evolution of the fields of research associated with non-linear laser-matter interaction. Production and acceleration of electrons up to 1 GeV over accelerating distances around 1 mm (100 meters for conventional accelerators) and hadron acceleration to 100 MeV, are the clearly visible results of this evolution.

The spectacular increase in brightness and decrease in pulse duration of particle beams will revolutionize the way of investigating matter. Fundamental events in biology, chemistry and solid-state physics can be recorded with angstrom space resolution to capture electronic, atomic or molecular transient dynamics. Source compactness, broad spectral range and perfect synchronization of particle and radiation bursts are unique properties that could extend the breadth of applications. The high peak current of laser–plasma electron beams could lead to compact XFEL facilities, on a size affordable by small-scale laboratories. High dissemination towards multidisciplinary users is then foreseen in fundamental science, but also in other fields. Finally, time-resolved experiments would significantly extend the field of investigation in the dynamics of matter, compared with currently available techniques using a visible pump and X-ray or visible probes.

It seems possible, at the first stage, to pump intermediate laser amplifiers (50 J level per beam at target) with laser diode technology instead of flash lamp based lasers. This change opens the possibility to strongly increase the laser quality, shot-to-shot stability and repetition rate, which follows the path to provide particle and radiation sources with enough reproducibility to be interesting to users and for further source development.

The end stage of ELI envisions a powerful laser, delivering a few kJ in 15 fs (~200 PW) with low repetition rate (minute based). Since all this stages will be constructed sequentially and the laser technology will evolve quickly, it is likely that the laser in 2015 will be further upgraded. Thus, it will be possible to get the 100 GeV electron laser acceleration, which is one of the goals ELI intends to achieve. The emergence of many PW-class systems, in the next few years, will be used for demonstrating the 10 GeV electron laser acceleration, thus ELI and the rest of the world ultra intense laser labs can nicely cooperate to sharpen their overall skills and knowhow in a collaborative network in this development. On the other hand, this energy level could trigger significant interest from the high energy physics community and could be a vehicle for getting their involvement.

Main outcomes of the Research Activity

The main outcome of this Research Activiy will be the development and realization of advanced and versatile sources of laser-accelerated particles (electrons, protons, ions) emitting in an unprecedented energy range. The sources will be simulated, designed, tested, prototyped, optimized, commissioned, and offered to users. Output characteristics and parameters of the particle sources will reflect actual demands of scientific community.

Laser-plasma accelerators of charged particles will be in the beginning of their use as particle sources for users. ELI will be the first facility in the world providing beam time for pump-probe experiments using the relativistic ultrashort beams and synchronized high-intensity lasers, electron beams, X-ray sources or attosecond sources, all that could be combined on a regular basis with the electron/ion sources for the advantage of the users. What makes ELI additionally unique is the ability to vary all these different secondary sources independently as allowed by having independent individual driving laser beams and adapting them optimal to the requirement of specific experiments.