Element | Decay | Energy/MeV | Air range/cm | Underwater range/µm | Range in ZnS(Ag)/µm |
Ra-226 | α | 4.761 | 3.290 | 33.292 | 26.113 |
U-234 | α | 4.756 | 3.240 | 32.786 | 25.716 |
Th-230 | α | 4.66 | 3.150 | 31.876 | 25.001 |
U-238 | α | 4.169 | 2.600 | 26.310 | 20.636 |
Th-232 | α | 3.933 | 2.500 | 25.298 | 19.843 |