Nuclide reference
Tm-170 — Thulium-170
The half-life of Tm-170 is 128.6 d. Main decay mode: β⁻ decay to Yb-170 (99.87%).
Identification
- Element
- Thulium (Tm)
- Atomic number Z
- 69
- Mass number A
- 170
- State
- Radioactive
Key quantities
- Half-life
- 128.6 d
- Specific activity
- 2.21e+14 Bq/g
- Gamma constant Γ (H*(10))
- 0.00089 µSv·m²/(MBq·h)
- Dose rate, 1 GBq at 1 m
- ≈ 0.89 µSv/h
- A1 / A2 for transport (SSR-6, НП-053-16)
- 3 TBq / 0.6 TBq
- D-value (НП-067-24)
- 20 TBq
Decay modes
- β⁻ decay → Yb-170 — 99.87 %
- electron capture → Er-170 — 0.131 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 84.2547 | 2.51 |
| 52.389 · X-ray line | 1.702 |
| 8.46983 · X-ray line | 1.387 |
| 78.7 | 0.00347 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 968 | 81.6 |
| 883.75 | 18.3 |
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.Dose rate example: point source, no shielding or scatter, Ḣ = Γ·A/r².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.