Nuclide reference
Hf-172 — Hafnium-172
The half-life of Hf-172 is 1.87 years. Main decay mode: electron capture to Lu-172m (100%).
Identification
- Element
- Hafnium (Hf)
- Atomic number Z
- 72
- Mass number A
- 172
- State
- Radioactive
Key quantities
- Half-life
- 1.87 years
- Specific activity
- 4.112e+13 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 0.6 TBq / 0.6 TBq
- D-value (НП-067-24)
- 0.04 TBq
Decay modes
- electron capture → Lu-172m — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 1,093.63 (Lu-172) | 63.12 |
| 54.07 · X-ray line | 62.55 |
| 52.389 (Lu-172) · X-ray line | 56.34 |
| 900.724 (Lu-172) | 30.11 |
| 181.525 (Lu-172) | 20.77 |
| 23.9331 | 20.34 |
| 810.064 (Lu-172) | 16.79 |
| 912.079 (Lu-172) | 15.4 |
| 125.812 | 11.3 |
| 78.7426 (Lu-172) | 10.67 |
Includes daughter nuclides in equilibrium: Lu-172 (yield per decay of Hf-172); the emitting nuclide is in brackets. Equilibrium is reached in about 47 d. In transient equilibrium a daughter's activity exceeds the parent's, so a yield can be above 100%.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁺, E max | 1,236 (Lu-172) | 0.0202 |
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.