Nuclide reference
Th-234 — Thorium-234
The half-life of Th-234 is 24.1 d. Main decay mode: β⁻ decay to Pa-234m (100%).
Identification
- Element
- Thorium (Th)
- Atomic number Z
- 90
- Mass number A
- 234
- State
- Radioactive
Key quantities
- Half-life
- 24.1 d
- Specific activity
- 8.567e+14 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)
- 2 TBq
Decay modes
- β⁻ decay → Pa-234m — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 13.3 · X-ray line | 7.04 |
| 63.29 | 3.665 |
| 92.38 | 2.13 |
| 92.8 | 2.1 |
| 1,001.03 (Pa-234m) | 0.8417 |
| 766.42 (Pa-234m) | 0.3173 |
| 112.81 | 0.21 |
| 742.813 (Pa-234m) | 0.1066 |
| 258.227 (Pa-234m) | 0.07642 |
| 17.0955 (Pa-234) · X-ray line | 0.07139 |
Includes daughter nuclides in equilibrium: Pa-234m, Pa-234 (yield per decay of Th-234); the emitting nuclide is in brackets. Equilibrium is reached in about 47 h.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 199.08 | 78 |
| 106.7 | 14 | |
| 106.28 | 6.4 | |
| 2,273.9 (Pa-234m) | 97.57 |
For β⁻ the endpoint (maximum) energy of the spectrum is given. ENDF/B-VIII.0.
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.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.