Nuclide reference
Cd-109 — Cadmium-109
The half-life of Cd-109 is 1.2632 years. Main decay mode: electron capture to Ag-109m (100%).
Identification
- Element
- Cadmium (Cd)
- Atomic number Z
- 48
- Mass number A
- 109
- State
- Radioactive
Key quantities
- Half-life
- 1.2632 years
- Specific activity
- 9.606e+13 Bq/g
- Gamma constant Γ (H*(10))
- 0.02853 µSv·m²/(MBq·h)
- Dose rate, 1 GBq at 1 m
- ≈ 28.5 µSv/h
- A1 / A2 for transport (SSR-6, НП-053-16)
- 30 TBq / 2 TBq
- D-value (НП-067-24)
- 20 TBq
Decay modes
- electron capture → Ag-109m — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 22.163 · X-ray line | 36.96 |
| 21.991 · X-ray line | 19.59 |
| 88.0336 (Ag-109m) | 3.7 |
Includes daughter nuclides in equilibrium: Ag-109m (yield per decay of Cd-109); the emitting nuclide is in brackets. Equilibrium is reached in about 4.6 min.
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.