Laser-plasma electron accelerators [1-6] result from the combined use of the capability of plasmas to sustain electric fields in excess of 1 GV/cm and the capability of high-power lasers to produce high amplitude relativistic electrostatic waves in these plasmas. The generation of monoenergetic electron bunches of up to 200 MeV was demonstrated for the first time in 2004  and the GeV barrier was overcome recently. More recent experiments [5,6] explored the possibility of controlling injection in order to reduce the beam energy spread or to improvement of beam quality and reproducibility. Possible near term applications for laser-plasma electron accelerators such as Free-Electron-Lasers, X-ray and gamma-ray sources, activation or fission, can take advantage of the unique properties of these beams: very short pulse (<20fs), very high charge per bunch (potentially 1 nC with state-of-the-art lasers), compactness (> 10GeV energy gain in 20 cm) and possible synchronization with laser pulses.
The current key issues on the development of laser-plasma accelerators are 1) laser quality and reproducibility, 2) controlled beam loading and 3) plasma source with laser guiding capability to extend the acceleration length to the maximum allowed by the laser group-velocity on the plasma. In this talk it will be presented a plasma source developed for laser-plasma accelerators . The plasma is produced inside a structured gas cell by a high-power short-rise-time electric discharge. The cell geometry constrains the discharge but allows for radial free expansion of the plasma column. The expansion of the column leads to a radial parabolic profile that can be used to guide the focused beam potentially extending the acceleration length to the plasma length. Current prototypes are compatible with the production of electron beams above 1 GeV. Current research aims the development of plasma channels compatible with future high-power lasers resulting in electron beams with energies above 10 GeV on a single acceleration stage.