Nuclide reference
Ce-139 — Cerium-139
Ce-139 की half-life 137.64 d है। मुख्य decay mode: electron capture → La-139 (100%)।
Identification
- तत्व
- Cerium (Ce)
- Atomic number Z
- 58
- Mass number A
- 139
- State
- Radioactive
Key quantities
- Half-life
- 137.64 d
- विशिष्ट गतिविधि
- 2.525e+14 Bq/g
- Gamma constant Γ (H*(10))
- 0.03929 µSv·m²/(MBq·h)
- Dose rate, 1 GBq at 1 m
- ≈ 39.3 µSv/h
- परिवहन के लिए A1 / A2 (SSR-6)
- 7 TBq / 2 TBq
- D-value (НП-067-24)
- 0.6 TBq
Decay modes
- electron capture → La-139 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 165.858 | 79.3 |
| 33.442 · X-ray line | 43.82 |
| 33.034 · X-ray line | 23.86 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
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 1 m पर H*(10) है, ICRP-107 spectra (NIST µ_en/ρ, ICRP-74 Table A.21) से गणना की गई, equilibrium में short-lived progeny सहित (जैसे Cs-137/Ba-137m, Ra-226 series); specific activity molar mass M ≈ mass number A का उपयोग करती है।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.