Decay modes are α, β−, β+, electron capture (EC) and isomeric transition (IT). EC results in the same daughter nucleus as would β+ decay. IT is a transition from a metastable excited state. Energies for β± decays are the maxima; average energies are roughly one-half the maxima.
| Isotope | t 1/2 | DecayMode(s) | Energy(MeV) | Percent | γ-Ray Energy(MeV) | Percent | |
|---|---|---|---|---|---|---|---|
| 3H | 12.33 y | β− | 0.0186 | 100% | |||
| 14C | 5730 y | β− | 0.156 | 100% | |||
| 13N | 9.96 min | β+ | 1.20 | 100% | |||
| 22Na | 2.602 y | β+ | 0.55 | 90% | γ | 1.27 | 100% |
| 32P | 14.28 d | β− | 1.71 | 100% | |||
| 35S | 87.4 d | β− | 0.167 | 100% | |||
| 36Cl | 3.00×105y | β− | 0.710 | 100% | |||
| 40K | 1.28×109y | β− | 1.31 | 89% | |||
| 43K | 22.3 h | β− | 0.827 | 87% | γs | 0.373 | 87% |
| 0.618 | 87% | ||||||
| 45Ca | 165 d | β− | 0.257 | 100% | |||
| 51Cr | 27.70 d | EC | γ | 0.320 | 10% | ||
| 52Mn | 5.59d | β+ | 3.69 | 28% | γs | 1.33 | 28% |
| 1.43 | 28% | ||||||
| 52Fe | 8.27 h | β+ | 1.80 | 43% | 0.169 | 43% | |
| 0.378 | 43% | ||||||
| 59Fe | 44.6 d | β−s | 0.273 | 45% | γs | 1.10 | 57% |
| 0.466 | 55% | 1.29 | 43% | ||||
| 60Co | 5.271 y | β− | 0.318 | 100% | γs | 1.17 | 100% |
| 1.33 | 100% | ||||||
| 65Zn | 244.1 d | EC | γ | 1.12 | 51% | ||
| 67Ga | 78.3 h | EC | γs | 0.0933 | 70% | ||
| 0.185 | 35% | ||||||
| 0.300 | 19% | ||||||
| others | |||||||
| 75Se | 118.5 d | EC | γs | 0.121 | 20% | ||
| 0.136 | 65% | ||||||
| 0.265 | 68% | ||||||
| 0.280 | 20% | ||||||
| others | |||||||
| 86Rb | 18.8 d | β−s | 0.69 | 9% | γ | 1.08 | 9% |
| 1.77 | 91% | ||||||
| 85Sr | 64.8 d | EC | γ | 0.514 | 100% | ||
| 90Sr | 28.8 y | β− | 0.546 | 100% | |||
| 90Y | 64.1 h | β− | 2.28 | 100% | |||
| 99mTc | 6.02 h | IT | γ | 0.142 | 100% | ||
| 113mIn | 99.5 min | IT | γ | 0.392 | 100% | ||
| 123I | 13.0 h | EC | γ | 0.159 | ≈100% | ||
| 131I | 8.040 d | β−s | 0.248 | 7% | γs | 0.364 | 85% |
| 0.607 | 93% | others | |||||
| others | |||||||
| 129Cs | 32.3 h | EC | γs | 0.0400 | 35% | ||
| 0.372 | 32% | ||||||
| 0.411 | 25% | ||||||
| others | |||||||
| 137Cs | 30.17 y | β−s | 0.511 | 95% | γ | 0.662 | 95% |
| 1.17 | 5% | ||||||
| 140Ba | 12.79 d | β− | 1.035 | ≈100% | γs | 0.030 | 25% |
| 0.044 | 65% | ||||||
| 0.537 | 24% | ||||||
| others | |||||||
| 198Au | 2.696 d | β− | 1.161 | ≈100% | γ | 0.412 | ≈100% |
| 197Hg | 64.1 h | EC | γ | 0.0733 | 100% | ||
| 210Po | 138.38 d | α | 5.41 | 100% | |||
| 226Ra | 1.60×103y | αs | 4.68 | 5% | γ | 0.186 | 100% |
| 4.87 | 95% | ||||||
| 235U | 7.038×108y | α | 4.68 | ≈100% | γs | numerous | <0.400% |
| 238U | 4.468×109y | αs | 4.22 | 23% | γ | 0.050 | 23% |
| 4.27 | 77% | ||||||
| 237Np | 2.14×106y | αs | numerous | γs | numerous | <0.250% | |
| 4.96 (max.) | |||||||
| 239Pu | 2.41×104y | αs | 5.19 | 11% | γs | 7.5×10−5 | 73% |
| 5.23 | 15% | 0.013 | 15% | ||||
| 5.24 | 73% | 0.052 | 10% | ||||
| others | |||||||
| 243Am | 7.37×103y | αs | Max. 5.44 | γs | 0.075 | ||
| 5.37 | 88% | others | |||||
| 5.32 | 11% | ||||||
| others |
Table
B1
Selected Radioactive Isotopes