Fig. 1

a Schematic of the hypoxia chamber. b Manufactured hypoxia chamber with the inlet and outlet valves connected to the tubing. Gas-impermeable 12 µm transparent PVDC window allows visual alignment and irradiation with low energy protons. c Stainless-steel dishes mounted with 3 µm Mylar for growing cells in monolayers and irradiating them with low energy protons. d Assembly of the stainless-steel dish inside the hypoxia chamber which can be sealed with a lid and mounted on a motorized stage. e Arrangement used for measuring the oxygen concentrations over time after gassing the hypoxia chambers using a Rapidox 1100Z detector (Cambridge Sensotec, Cambridge UK)