Nuclide reference
Sr-85 — Strontium-85
The half-life of Sr-85 is 64.84 d. Main decay mode: β⁺ decay / electron capture to Rb-85 (100%).
Identification
- Element
- Strontium (Sr)
- Atomic number Z
- 38
- Mass number A
- 85
- State
- Radioactive
Key quantities
- Half-life
- 64.84 d
- Specific activity
- 8.766e+14 Bq/g
- Gamma constant Γ (H*(10))
- 0.08215 µSv·m²/(MBq·h)
- Dose rate, 1 GBq at 1 m
- ≈ 82.2 µSv/h
- A1 / A2 for transport (SSR-6, НП-053-16)
- 2 TBq / 2 TBq
- D-value (НП-067-24)
- 0.1 TBq
Decay modes
- β⁺ decay / electron capture → Rb-85 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 514.007 | 95.71 |
| 13.395 · X-ray line | 33.47 |
| 13.336 · X-ray line | 17.4 |
| 868.06 | 0.012 |
| 151.18 | 0.001152 |
| 354.06 | 0.00048 |
| 362.82 | 0.00048 |
| 716.87 | 0.0003072 |
| 129.8 | 0.00024 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
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.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.