Nuclide reference
Os-191 — Osmium-191
The half-life of Os-191 is 15.4 d. Main decay mode: β⁻ decay to Ir-191m (100%).
Identification
- Element
- Osmium (Os)
- Atomic number Z
- 76
- Mass number A
- 191
- State
- Radioactive
Key quantities
- Half-life
- 15.4 d
- Specific activity
- 1.643e+15 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 10 TBq / 2 TBq
- D-value (НП-067-24)
- 2 TBq
Decay modes
- β⁻ decay → Ir-191m — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 64.896 (Ir-191m) · X-ray line | 27.67 |
| 129.431 (Ir-191m) | 26.5 |
| 10.7674 (Ir-191m) · X-ray line | 19.66 |
| 82.427 (Ir-191m) | 0.031 |
Includes daughter nuclides in equilibrium: Ir-191m (yield per decay of Os-191); the emitting nuclide is in brackets. Equilibrium is reached in about 34 s.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 141.42 | 100 |
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.