Table 1.
227Th Decay Scheme: Photon Energies with an Abundance >1% Are Shown
| Decay | Decay mode | Half-life | Principal photon energies (keV) (% abundance) |
|---|---|---|---|
| 227Th→223Ra | α | 18.7 days | 12.3 (21.0), 50.1 (8.0), 79.7 (1.7), 85.4 (1.2), 88.5 (2.0), 94.0 (1.4), 210.7 (1.1), 236.0 (12.3), 256.3 (7.0), 286.1 (1.5), 300.0 (2.3), 304.5 (1.2) 329.9 (2.7), 334 (1.1) |
| 223Ra→219Rn | α | 11.4 days | 11.7 (25.0), 81.1 (15.0), 83.8 (24.9), 94.9 (11.3), 122.3 (1.2), 144.2 (3.2), 154.2 (5.6), 269.5 (13.7), 323.9 (3.9), 338.3 (2.8), 445.0 (1.3) |
| 219Rn→215Po | α | 4.0 s | 11.1 (1.1), 271.2 (10.8), 401.8 (6.4) |
| 215Po→211Pb | α | 1.8 ms | |
| 211Pb→211Bi | β− | 36.1 min | 404.9 (3.8), 427.1 (1.8), 832.0 (3.5) |
| 211Bi→207Tl | α | 2.1 min | 10.3 (1.1), 72.9 (1.3), 351.1 (12.9) |
| 207Tl→207Pb | β− | 4.8 min |