Nuclide reference
Te-131m — Tellurium-131m
The half-life of Te-131m is 1.3854 d. Main decay mode: β⁻ decay to I-131 (74.1%).
Identification
- Element
- Tellurium (Te)
- Atomic number Z
- 52
- Mass number A
- 131
- State
- Radioactive
Key quantities
- Half-life
- 1.3854 d
- Specific activity
- 2.662e+16 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 0.7 TBq / 0.5 TBq
- D-value (НП-067-24)
- 0.04 TBq
Decay modes
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 773.67 | 36.82 |
| 852.21 | 20.28 |
| 149.716 (Te-131) | 18.05 |
| 793.75 | 13.37 |
| 1,125.46 | 11.02 |
| 1,206.6 | 9.411 |
| 334.27 | 9.225 |
| 27.472 · X-ray line | 7.921 |
| 102.06 | 7.656 |
| 782.49 | 7.507 |
Includes daughter nuclides in equilibrium: Te-131 (yield per decay of Te-131m); the emitting nuclide is in brackets. Equilibrium is reached in about 3 h.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 436.89 | 35.21 |
| 518.02 | 15.84 | |
| 2,083.1 (Te-131) | 15.55 | |
| 1,630.8 (Te-131) | 5.676 |
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.