• R. Bachelard, F. Briquez, M.-E. Couprie, A. Loulergue
  SOLEIL, Gif-sur-Yvette
• A. Ben Ismail, S. Corde, J. Faure, G. Lambert, O. Lundh, V. Malka, A. Rousse, K. Ta Phuoc
  LOA, Palaiseau
• G. De Ninno
  ELETTRA, Basovizza
• M. Labat
  ENEA C.R. Frascati, Frascati (Roma)

In the quest for compact FEL ultra-compact sources, a test experiment is under preparation, to couple an electron beam from a laser driven plasma accelerator, stable and tunable in energy, to an undulator. The electron beam is generated in the colliding laser pulses scheme, by focusing two short and intense laser pulse in an underdense plasma plume. The electron bunch has an energy tunable in up to a few hundreds MeV with 1% energy spread, a length 10 fs, a charge in the 10 pC range, while its radius and divergence are respectively 1μm and 3 mrad. As a first step toward a FEL experiment, the transport and radiation through an undulator of this short and compact electron beam is studied. The spontaneous emission through a 60 cm undulator in the 40-120 nm range is presented, and criteria to reach the threshold of Self-Amplified Spontaneous Emission are discussed.