Ion acceleration by radiation pressure in thin and thick targets

Radiation Pressure Acceleration (RPA) by circularly polarized laser pulses is emerging as a promising way to obtain efficient acceleration of ions. We briefly review theoretical work on the topic, aiming at characterizing suitable experimental scenarios. We discuss the two reference cases of RPA, namely the thick target (Hole Boring) and the (ultra)thin target (Light Sail) regimes. The different scaling laws of the two regimes, the related experimental challenges and their suitability for foreseen applications are discussed.