Nuclide reference
Fr-221 — Francium-221
Fr-221 की half-life 4.9 min है। मुख्य decay mode: α decay → At-217 (100%)।
Identification
- तत्व
- Francium (Fr)
- Atomic number Z
- 87
- Mass number A
- 221
- State
- Radioactive
Key quantities
- Half-life
- 4.9 min
- विशिष्ट गतिविधि
- 6.424e+18 Bq/g
- Gamma constant Γ
- —
- D-value (НП-067-24)
- —
Decay modes
- α decay → At-217 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 218.12 | 11.38 |
| 81.517 · X-ray line | 1.357 |
| 78.948 · X-ray line | 0.8193 |
| 410.64 | 0.1201 |
| 100.25 | 0.1018 |
| 171.83 | 0.07736 |
| 150.21 | 0.04784 |
| 359.86 | 0.04072 |
| 382.34 | 0.03359 |
| 257.9 (At-217) | 0.0287 |
Includes daughter nuclides in equilibrium: At-217 (yield per decay of Fr-221); the emitting nuclide is in brackets. Equilibrium is reached in about 0.23 s.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| α | 6,341 | 83.4 |
| 6,126.3 | 15.1 | |
| 6,243 | 1.34 | |
| 7,066.9 (At-217) | 99.9 |
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।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.