The interaction of ultraintense laser pulses with ultrathin foils leads to efficient acceleration of ions from within the target, through advanced mechanisms such as radiation pressure acceleration or transparency-enhanced processes. These mechanisms have recently resulted in important experimental advances, delivering proton and carbon beams with enhanced

properties, employing PW-class laser pulses. We propose an experiment to extend these studies to the multi-PW regime, by taking advantage of the unique interaction conditions provided by the APOLLON 3 PW beam. By focusing the contrastenhanced laser pulse onto ultrathin targets of suitable thickness, at intensities exceeding 1022 W/cm2, we aim to benchmark

predictions for ion acceleration in this largely unexplored regime, which are highly promising for the all-optical delivery of protons and carbon ions at unprecedented energies.