Nuclide reference
Mg-28 — Magnesium-28
The half-life of Mg-28 is 20.915 h. Main decay mode: β⁻ decay to Al-28 (100%).
Identification
- Element
- Magnesium (Mg)
- Atomic number Z
- 12
- Mass number A
- 28
- State
- Radioactive
Key quantities
- Half-life
- 20.915 h
- Specific activity
- 1.98e+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)
- 0.02 TBq
Decay modes
- β⁻ decay → Al-28 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 1,778.85 (Al-28) | 100.2 |
| 30.64 | 66 |
| 1,342.25 | 52.6 |
| 941.45 | 38.3 |
| 400.69 | 36.6 |
| 1,372.89 | 4.7 |
| 1,589.36 | 4.2 |
| 1.46917 · X-ray line | 0.6523 |
| 1.4687 · X-ray line | 0.3286 |
| 1,620 | 0.3 |
Includes daughter nuclides in equilibrium: Al-28 (yield per decay of Mg-28); the emitting nuclide is in brackets. Equilibrium is reached in about 16 min.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 458.92 | 95 |
| 211.75 | 5 | |
| 859.63 | 0.31 | |
| 2,863.4 (Al-28) | 100.2 |
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.