Nowadays there is a large demand from the life sciences and material science community for high brightness coherent photon sources – XFELs – currently driven by expensive classical accelerators affordable only for international collaborations. Laser-driven XFELs, on the other hand, will be compact sources with overall length of several tens of meters and with cost affordable for larger universities or national laboratories.

The ELI Beamlines LUX team has been intensively working in collaboration with University of Hamburg on the development of the LUX. As a next step towards laser driven XFEL, this proposal focuses on the following research areas:

1) Development of advanced plasma diagnostics methods and various electron injection schemes to enhance understanding of the electron injection and acceleration and decrease the energy spread of the accelerated electron bunch to enable FEL level gain in the future undulator section;

2) Study in detail principles of plasma based electron beam transport lenses and develop advanced electron beam transport matching the requirements of the FEL.

Since early phase of this program LUIS will also provide ELI Beamlines users photon beams using the LUX undulator and auxiliary beams for pump and probe experiments. In parallel with this program the multi-undulator section of the FEL will be developed and commissioned in collaboration with University of Hamburg, which will provide ELI Beamlines EUV FEL very attractive for international users.

When accomplished, the LUIS will enable operation at 100 Hz or more, given its target section design. The main limitation of the repetition rate will thus come from the 100-TW class laser driver system. Current 100-TW laser systems run at most at 10 Hz repetition rate. However, the L3 HAPLS system technology, which will enable L3 to run with 30 J pulses at 10 Hz (300 W average power), can be adopted for construction of 100-TW 100 Hz laser system for driving LUIS based XFEL.

At the early stage of the operation the LUIS setup will produce the incoherent photon radiation in the ‘water-window’ range (lambda(ph,1)= 2÷5 nm) for different user’s experiments with the photon flux more than 10^5 per pulse in the 1% bandwidth, the peak brilliance more than 10^20 photons/pulse/mm2/mrad2/0.1%BW. During the realization of the LUIS-FEL program (‘laser-driven’ compact FEL) the LUIS setup will be able to deliver the coherent photon radiation with the ‘state-of-art’ parameters for the ‘soft’ and ‘hard’ X-ray beams: the photon flux more than 10^11per pulse in the 0.1% bandwidth, the peak brilliance more than 10^29 photons/pulse/mm2/mrad2/0.1%BW.