DESIGN CONSIDERATIONS FOR TABLE-TOP FELs∗

Refinements in laser technology (few-cycle pulse gen-eration, chirped pulse amplification) combined with super-computer-based plasma simulations have brought the dis-cipline of relativistic laser-matter interaction to a new level of predictability. This was recently demonstrated by the generation of brilliant electron bunches with energies on the 0.1-1-GeV-scale. Our plan is to utilize such laser-accelerated electron beams to realize table-top FELs. The essential feature of those electrons is their ultra-high beam current of up to few 100 kA in 10 fs. Such high currents make small-period undulators realistic, which require less electron energy for the same FEL wavelength. Together with low emittance and relatively large Pierce parameters the undulator length for reaching SASE saturation should be as small as only meter-scales. In this paper we present our first basic design considerations based upon start-to-end simulations including 3d PIC codes and GENESIS 1.3. In contrast to large-scale XFELs, which will be dedicated user facilities, our aim is to deliver the proof-of-principle of table-top FELs, starting from the VUV to the X-ray range. The present paper will give a short overview of the ba-sic design-considerations for table-top FELs, while a more detailed manuscript will be submitted to Nucl. Instrum