Fig. 2

a Hypoxia chamber assembled with the cell dish. b Irradiation set up of hypoxia chamber inside the re-entry tube. The chamber is slid on the metal rail (blue arrows) towards the end of the tube and just before and during radiation the chamber is tilted vertically as shown in c using a motorized mount such that the transparent PVDC window of the hypoxia chamber is facing the Kapton window through which the laser-accelerated proton beam emerges and irradiates the cells grown on the Mylar mounted in a stainless steel dish inside the hypoxia chambers. d Comparison of EBT3 films irradiated with a 30 MeV proton beam outside and inside the chamber e Lineout across dose profiles in (d). f Energy spectra of 15 MeV proton beam (blue curve) crossing the 2 cm of air gap inside the chamber with (red line) and without (dashed pink line) the 12.5 μm Saran window of the hypoxia chamber, obtained using the GEANT 4 Monte Carlo Simulation