Due to the high electric field strength of more than 10^12 V/m, high power lasers are attractive for the acceleration of ions such as protons within a micron-scaled accelerating structure to more than hundred megaelectron-volts (MeV). It allows to construct compact accelerator concepts to provide many attractive applications such as in medicin as well as to realize short pulsed neutron sources (a few 10-12 s of pulse duration). Several acceleration mechanisms are discussed : Most important schemes for laser induced ion acceleration is the Target Normal Sheath Acceleration (TNSA) as well as radiation pressure mechanisms (RPA). Latter is of present interest because it opens up the possibility of generating mono energetic ion beams with energies up to the gigaelectron-volt (GeV) regime. This is attractive in nuclear and particle physics applications.

Further issues are laser-plasma accelerators to generate relativistic electron beams. The acceleration processes can be separated in two principle scenarios : The particle beam-driven plasma wake field acceleration (PWFA), and the laser-driven plasma wake field acceleration (LWFA). The PWFA leads to the so-called plasma blow-out regime behind the driver beam. The LWFA can form a highly non-linear broken plasma wave regime which leads to a plasma cavity, the so called “bubble”. Both, the blow-out regime and the bubble are very strong focusing potentials (electric field strength of more than 100 GV/m), resulting in trapped electrons. The trapped electrons generate a quasi mono-energetic bunch which is relativisticly accelerated by the plasma cavity. The LWFA and the PWFA are very promising mechanisms in the production of bright and coherent short pulsed hard x-ray as well as gamma-ray sources.

This presentation gives an overview of the state-of-the-art laser-driven particle acceleration concepts and their applications.

Contact : blanc@ill.fr