Nuclide reference
Th-227 — Thorium-227
The half-life of Th-227 is 18.68 d. Main decay mode: α decay to Ra-223 (100%).
Identification
- Element
- Thorium (Th)
- Atomic number Z
- 90
- Mass number A
- 227
- State
- Radioactive
Key quantities
- Half-life
- 18.68 d
- Specific activity
- 1.139e+15 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 10 TBq / 0.005 TBq
- D-value (НП-067-24)
- 0.08 TBq
Decay modes
- α decay → Ra-223 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 235.96 | 17.5 |
| 50.13 | 11.38 |
| 256.23 | 9.503 |
| 329.85 | 3.99 |
| 88.473 · X-ray line | 3.901 |
| 299.98 | 2.993 |
| 79.69 | 2.643 |
| 289.59 | 2.625 |
| 85.76 · X-ray line | 2.388 |
| 286.09 | 2.363 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| α | 6,038 | 24.2 |
| 5,977.7 | 23.5 | |
| 5,756.9 | 20.4 | |
| 5,708.8 | 8.3 |
Related calculators
Other isotopes of this element
Reference data vs computed valuesHalf-life, gamma lines and D-value are reference data (ENDF/B-VIII.0, НП-067-24).Gamma constant Γ is H*(10) at 1 m computed from ICRP-107 spectra (NIST µ_en/ρ, ICRP-74 Table A.21) including short-lived progeny in equilibrium (e.g. Cs-137/Ba-137m, Ra-226 series); specific activity uses molar mass M ≈ mass number A.K-series X-ray energies are from NIST SRD 128 (Deslattes et al., 2003): in ENDF/B-VIII.0 they are given to 1 % and shifted by up to 0.7 keV for heavy elements. L-series lines and all yields are ENDF/B-VIII.0.