Nuclide reference
Cm-250 — Curium-250
The half-life of Cm-250 is 8,300 years. Main decay mode: spontaneous fission (74%).
Identification
- Element
- Curium (Cm)
- Atomic number Z
- 96
- Mass number A
- 250
- State
- Radioactive
Key quantities
- Half-life
- 8,300 years
- Specific activity
- 6.375e+9 Bq/g
- Gamma constant Γ
- —
- D-value (НП-067-24)
- —
Decay modes
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 1,078.86 (Am-246m) | 5 |
| 43.81 (Pu-246) | 4.5 |
| 798.8 (Am-246m) | 4.464 |
| 223.75 (Pu-246) | 4.23 |
| 106.47 (Pu-246) · X-ray line | 3.663 |
| 989.125 (Bk-250) | 3.6 |
| 14.6137 (Pu-246) · X-ray line | 3.322 |
| 1,062.04 (Am-246m) | 3.085 |
| 1,031.85 (Bk-250) | 2.848 |
| 1,036 (Am-246m) | 2.286 |
Includes daughter nuclides in equilibrium: Bk-250, Pu-246, Am-246m (yield per decay of Cm-250); the emitting nuclide is in brackets. Equilibrium is reached in about 76 d.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 748.15 (Bk-250) | 6.672 |
| 177.26 (Pu-246) | 16.38 | |
| 1,302.1 (Am-246m) | 6.714 | |
| 1,539.3 (Am-246m) | 2.898 |
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.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.