Fig. 1. Schematic diagram of electron FLASH-RT experimental platform

Fig. 2. Film is placed parallel to the beam direction

Fig. 3. Monte Carlo simulation diagram

Fig. 4. Relative deviation of the dose at different depths under five independent repeated experiments

Fig. 5. Off-axis ratio curves at different water-layer thicknesses

Fig. 6. EBT3 film and MC dose distribution curve

Fig. 7. Off-axis ratio dose distribution curve of EBT3 film

Fig. 8. Effect of water-layer thickness on the Percentage Depth Dose (PDD)

Fig. 9. Depth dose distribution curves of EBT3 film and MC simulation

Fig. 10. Two-dimensional dose distribution of EBT3 film and MC simulation

Fig. 11. PDD curves for electron beams at different energies

Fig. 12. PDD of the electron beam varies with field sizes

Fig. 13. Lateral electron distribution in central-axis field size

Fig. 14. Off-axis ratio curves under different field sizes