Nuclide reference
Pm-149 — Promethium-149
The half-life of Pm-149 is 2.2117 d. Main decay mode: β⁻ decay to Sm-149 (100%).
Identification
- Element
- Promethium (Pm)
- Atomic number Z
- 61
- Mass number A
- 149
- State
- Radioactive
Key quantities
- Half-life
- 2.2117 d
- Specific activity
- 1.466e+16 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 2 TBq / 0.6 TBq
- D-value (НП-067-24)
- 6 TBq
Decay modes
- β⁻ decay → Sm-149 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 285.95 | 3.1 |
| 40.119 · X-ray line | 0.1191 |
| 859.46 | 0.1085 |
| 590.88 | 0.06913 |
| 39.524 · X-ray line | 0.0658 |
| 833.4 | 0.03317 |
| 830.53 | 0.03255 |
| 277.09 | 0.02883 |
| 22.52 | 0.0248 |
| 881.98 | 0.02387 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 1,071.5 | 95.9 |
| 785.56 | 3.4 | |
| 189.53 | 0.136 | |
| 480.61 | 0.09 |
For β⁻ the endpoint (maximum) energy of the spectrum is given. ENDF/B-VIII.0.
Related calculators
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.