Scaling Laws for Proton Acceleration from the Rear Surface of Laser-Irradiated Thin Foils.

In the last few years, intense research has been conducted on the topic of laser-accelerated ion sources and their applications. Ultra-bright beams of multi-MeV protons are produced by irradiating thin metallic foils with ultra-intense short laser pulses. These sources open new opportunities for ion beam generation and control, and could stimulate development of compact ion accelerators for many applications, in particular proton therapy of deep-seated tumours. Here we show that scaling laws deduced from fluid models reproduce well the acceleration of proton beams for a large range of laser and target parameters. These scaling laws show that, in our regime, there is an optimum in the laser pulse duration of ∼200 fs–1 ps, with a needed laser energy level of 30 to 100 J, in order to achieve e.g. 200 MeV energy protons necessary for proton therapy. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]