Nuclide reference
Sm-153 — Samarium-153
The half-life of Sm-153 is 1.9375 d. Main decay mode: β⁻ decay to Eu-153 (100%).
Identification
- Element
- Samarium (Sm)
- Atomic number Z
- 62
- Mass number A
- 153
- State
- Radioactive
Key quantities
- Half-life
- 1.9375 d
- Specific activity
- 1.63e+16 Bq/g
- Gamma constant Γ (H*(10))
- 0.01739 µSv·m²/(MBq·h)
- Dose rate, 1 GBq at 1 m
- ≈ 17.4 µSv/h
- A1 / A2 for transport (SSR-6, НП-053-16)
- 9 TBq / 0.6 TBq
- D-value (НП-067-24)
- 2 TBq
Decay modes
- β⁻ decay → Eu-153 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 41.543 · X-ray line | 30.67 |
| 103.18 | 29.25 |
| 40.904 · X-ray line | 16.96 |
| 69.673 | 4.733 |
| 97.431 | 0.7722 |
| 75.4221 | 0.1931 |
| 83.3672 | 0.1916 |
| 89.4859 | 0.158 |
| 172.853 | 0.07371 |
| 531.4 | 0.0547 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 703.62 | 49.4 |
| 633.95 | 31.3 | |
| 806.8 | 18.4 | |
| 709.37 | 0.6 |
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.Dose rate example: point source, no shielding or scatter, Ḣ = Γ·A/r².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.