Nuclide reference
Sr-91 — Strontium-91
The half-life of Sr-91 is 9.63 h. Main decay mode: β⁻ decay to Y-91m (58.84%).
Identification
- Element
- Strontium (Sr)
- Atomic number Z
- 38
- Mass number A
- 91
- State
- Radioactive
Key quantities
- Half-life
- 9.63 h
- Specific activity
- 1.323e+17 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 0.3 TBq / 0.3 TBq
- D-value (НП-067-24)
- 0.06 TBq
Decay modes
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 555.57 (Y-91m) | 61.13 |
| 1,024.3 | 33.5 |
| 749.8 | 23.68 |
| 652.9 | 8.04 |
| 925.8 | 3.852 |
| 652.3 | 2.982 |
| 620.1 | 1.776 |
| 14.958 (Y-91m) · X-ray line | 1.107 |
| 274.7 | 1.035 |
| 1,413.4 | 0.9815 |
Includes daughter nuclides in equilibrium: Y-91m (yield per decay of Sr-91); the emitting nuclide is in brackets. Equilibrium is reached in about 6.3 h.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 1,113.1 | 34.8 |
| 2,693 | 28.6 | |
| 1,387.6 | 25.1 | |
| 2,040 | 3.4 |
For β⁻ the endpoint (maximum) energy of the spectrum is given. ENDF/B-VIII.0.
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.