Nuclide reference
Te-127m — Tellurium-127m
The half-life of Te-127m is 109 d. Main decay mode: isomeric transition to Te-127 (97.6%).
Identification
- Element
- Tellurium (Te)
- Atomic number Z
- 52
- Mass number A
- 127
- State
- Radioactive
Key quantities
- Half-life
- 109 d
- Specific activity
- 3.49e+14 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 20 TBq / 0.5 TBq
- D-value (НП-067-24)
- 3 TBq
Decay modes
- isomeric transition → Te-127 — 97.6 %
- β⁻ decay → I-127 — 2.4 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 27.472 · X-ray line | 19.7 |
| 27.202 · X-ray line | 10.49 |
| 417.9 (Te-127) | 0.9697 |
| 57.63 | 0.5024 |
| 360.3 (Te-127) | 0.1319 |
| 88.26 | 0.08355 |
| 202.9 (Te-127) | 0.05682 |
| 215.1 (Te-127) | 0.03792 |
| 57.63 (Te-127) | 0.02909 |
| 658.9 | 0.01232 |
Includes daughter nuclides in equilibrium: Te-127 (yield per decay of Te-127m); the emitting nuclide is in brackets. Equilibrium is reached in about 2.7 d.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 728.62 | 2.376 |
| 702 (Te-127) | 96.76 | |
| 284.07 (Te-127) | 1.166 | |
| 499.14 (Te-127) | 0.02645 |
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.