Nuclide reference
Pm-148m — Promethium-148m
The half-life of Pm-148m is 41.29 d. Main decay mode: β⁻ decay to Sm-148 (95.8%).
Identification
- Element
- Promethium (Pm)
- Atomic number Z
- 61
- Mass number A
- 148
- State
- Radioactive
Key quantities
- Half-life
- 41.29 d
- Specific activity
- 7.906e+14 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 0.8 TBq / 0.7 TBq
- D-value (НП-067-24)
- 0.03 TBq
Decay modes
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 550.27 | 94.87 |
| 629.97 | 89 |
| 725.7 | 32.84 |
| 1,013.81 | 20.28 |
| 414.07 | 18.66 |
| 915.33 | 17.17 |
| 288.11 | 12.56 |
| 599.74 | 12.54 |
| 501.26 | 6.746 |
| 611.26 | 5.482 |
Lines of the nuclide itself (ENDF/B-VIII.0).
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 411.85 | 54.61 |
| 699.96 | 22.13 | |
| 510.33 | 17.63 | |
| 2,470 (Pm-148) | 2.679 |
For β⁻ the endpoint (maximum) energy of the spectrum is given. ENDF/B-VIII.0. Includes daughter nuclides in equilibrium: Pm-148 (yield per decay of Pm-148m); the emitting nuclide is in brackets. Equilibrium is reached in about 43 d.
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.