Nuclide reference
Er-169 — Erbium-169
The half-life of Er-169 is 9.392 d. Main decay mode: β⁻ decay to Tm-169 (100%).
Identification
- Element
- Erbium (Er)
- Atomic number Z
- 68
- Mass number A
- 169
- State
- Radioactive
Key quantities
- Half-life
- 9.392 d
- Specific activity
- 3.044e+15 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 40 TBq / 1 TBq
- D-value (НП-067-24)
- 200 TBq
Decay modes
- β⁻ decay → Tm-169 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 8.41017 | 0.1705 |
| 109.779 | 0.001306 |
| 118.189 | 0.00014 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 351.4 | 55 |
| 342.99 | 45 |
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.