Dose dependent biological damage of tumour cells by laser-accelerated proton beams

We report on the irradiation of in vitro tumour cells with laser-accelerated proton pulses showing dose dependent biological damage. This experiment, paving the way for future radiobiological studies with laser-accelerated protons, demonstrates for the first time the simultaneous and reliable availability of all components indispensable for systematic radiobiological studies: A laser-plasma accelerator providing stable proton spectra with maximum energy exceeding 15 MeV and applicable doses of a few Gy within few minutes, a beam transport and filtering system, an in-air irradiation site, a dedicated dosimetry system providing both online dose monitoring and a precise absolute dose information applied to the cell sample, and the full infrastructure for analysing radiation induced damage in cells.