Ion acceleration driven by ultra-short, ultra-intense pulses

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The project aims to investigate an important process taking place during the interaction of very high power laser radiation with matter, namely the acceleration of ions to very high energies. This process, capable to reach over micormetric distances the energies that are otherwise obtained in large scale accelerators, has been made possible very recently due to the development of a new class of laser systems based on a principle called Chirped Pulse Amplification. The ions are accelerated by ultralarge electric fields set at thesurface of laser irradiated foils by escaping high energy electrons which have acquired energy directly from the laser. The energy of the ion scales with the intensity of the laser radiation used to accelerate them, and so called scaling laws relationships can be used to predict energies reachable in the future and to compare experimental results with relevant theory in order to test the understanding of the accelerating mechanisms.A novel laser facility, accessing unprecedented intensity regimes, called GEMINI will be opened up to experiments in the second half of 2007. This facility will achieve enormous fluxes of laser energies (larger than 10^21 W/cm^2) by concentrating light in ultrashort pulses, of duration 30 femtoseconds (1 fs =10^-15 s), in spots with radius of the order of a micrometer. Theoretical predictions suggest that at this intensities it will be possible to accelerate protons up to energies close to the ones required for groundbreaking applications such as cancer radiotherapy. This projects aims to exploit the unique opportunities offered by the GEMINI development to investigate ion acceleration in this novel ultraintense, ultrashort regime, and understand the details of the mechanisms taking place. We also aim to investigate some unexplored aspects of laser-matter interactions in the ultraintense regime by applying a technique (proton probing) developed by our group to diagnose the interaction of the GEMINI laser pulses with solid and gaseous targets.Another important aim of the project is to train a PhD student in this exciting area of research, and provide him/her with the skills necessary to continue a research career and become a skilled user of future scientific installations.