Fig. 1. Device diagram of experimental platform

Fig. 2. Structure diagram of integral energy measurement system

Fig. 3. Transmitted electron intensity varies with inclination angle α

Fig. 4. 2D angular distribution of outgoing electrons in equilibrium at different inclination angles

Fig. 5. Transmission electron transmittance (f) and evolution of 2D angular distribution with time

Fig. 6. Transmission electron energy integral spectrum

Fig. 7. The 3D model of PET sample used in CASINO and simulation of internal deposition of PET

Fig. 8. Electron emission path diagram of internal deposition of PET