Nuclide reference
Tl-204 — Thallium-204
The half-life of Tl-204 is 3.783 years. Main decay mode: β⁻ decay to Pb-204 (97.08%).
Identification
- Element
- Thallium (Tl)
- Atomic number Z
- 81
- Mass number A
- 204
- State
- Radioactive
Key quantities
- Half-life
- 3.783 years
- Specific activity
- 1.714e+13 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 10 TBq / 0.7 TBq
- D-value (НП-067-24)
- 20 TBq
Decay modes
- β⁻ decay → Pb-204 — 97.08 %
- electron capture → Hg-204 — 2.92 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 70.819 · X-ray line | 0.811 |
| 68.894 · X-ray line | 0.4784 |
| 9.97662 · X-ray line | 0.394 |
| 11.8626 · X-ray line | 0.3249 |
| 80.256 · X-ray line | 0.1734 |
| 79.824 · X-ray line | 0.08958 |
| 14.0093 · X-ray line | 0.05986 |
| 82.528 · X-ray line | 0.04136 |
| 9.42205 · X-ray line | 0.03833 |
| 82.425 · X-ray line | 0.02112 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 763.76 | 97.08 |
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.