Nuclide reference
Ra-222 — Radium-222
Ra-222 की half-life 36.17 s है। मुख्य decay mode: α decay → Rn-218 (100%)।
Identification
- तत्व
- Radium (Ra)
- Atomic number Z
- 88
- Mass number A
- 222
- State
- Radioactive
Key quantities
- Half-life
- 36.17 s
- विशिष्ट गतिविधि
- 5.198e+19 Bq/g
- Gamma constant Γ
- —
- D-value (НП-067-24)
- —
Decay modes
- α decay → Rn-218 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 324.31 | 2.77 |
| 609.31 (Rn-218) | 0.1241 |
| 83.789 · X-ray line | 0.07582 |
| 81.071 · X-ray line | 0.04599 |
| 799.7 (Po-214) | 0.01036 |
| 328.9 | 0.004 |
| 472.59 | 0.0039 |
| 840.18 | 0.0028 |
| 515.83 | 0.00142 |
| 653.14 | 0.00024 |
Includes daughter nuclides in equilibrium: Rn-218, Po-214 (yield per decay of Ra-222); the emitting nuclide is in brackets. Equilibrium is reached in about 0.25 s. Equilibrium with radon requires a sealed source.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| α | 6,559 | 96.9 |
| 6,241 | 3.05 | |
| 7,129.2 (Rn-218) | 99.97 | |
| 7,686.8 (Po-214) | 100.1 |
Related calculators
इसी element के अन्य isotopes
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।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.