Nuclide reference
Mo-99 — Molybdenum-99
Mo-99 की half-life 2.749 d है। मुख्य decay mode: β⁻ decay → Tc-99m (87.89%)।
Identification
- तत्व
- Molybdenum (Mo)
- Atomic number Z
- 42
- Mass number A
- 99
- State
- Radioactive
Key quantities
- Half-life
- 2.749 d
- विशिष्ट गतिविधि
- 1.775e+16 Bq/g
- Gamma constant Γ (H*(10))
- 0.02404 µSv·m²/(MBq·h)
- Dose rate, 1 GBq at 1 m
- ≈ 24 µSv/h
- परिवहन के लिए A1 / A2 (SSR-6)
- 1 TBq / 0.6 TBq
- D-value (НП-067-24)
- 0.3 TBq
Decay modes
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 140.511 (Tc-99m) | 86.05 |
| 739.5 | 12.26 |
| 181.068 | 6.142 |
| 140.511 | 4.536 |
| 777.921 | 4.303 |
| 18.368 (Tc-99m) · X-ray line | 3.928 |
| 18.251 (Tc-99m) · X-ray line | 2.066 |
| 366.421 | 1.204 |
| 40.5832 | 1.064 |
| 822.972 | 0.1349 |
Includes daughter nuclides in equilibrium: Tc-99m (yield per decay of Mo-99); the emitting nuclide is in brackets. Equilibrium is reached in about 46 h.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 1,214.3 | 82.2 |
| 436.36 | 16.4 | |
| 847.88 | 1.16 | |
| 352.93 | 0.146 |
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 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.