Nuclide reference

Cm-250 — Curium-250

Cm-250 की half-life 8,300 years है। मुख्य decay mode: spontaneous fission (74%)।

Identification

तत्व
Curium (Cm)
Atomic number Z
96
Mass number A
250
State
Radioactive

Key quantities

Half-life
8,300 years
विशिष्ट गतिविधि
6.375e+9 Bq/g
Gamma constant Γ
—
D-value (НП-067-24)
—

Decay modes

  • spontaneous fission — 74 %
  • α decay → Pu-246 — 18 %
  • β⁻ decay → Bk-250 — 8 %

Main gamma lines

Energy, keVYield, %
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 line3.663
989.125 (Bk-250)3.6
14.6137 (Pu-246) · X-ray line3.322
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

RadiationEnergy, keVYield, %
β⁻, E max748.15 (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 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.

Curium-250 (Cm-250) — reference data

What is in the card

This card gathers the key data of radionuclide Cm-250 in one place: half-life, decay modes, main gamma lines, alpha and beta particle energies, gamma constant, specific activity and the D-value for source categorization. Decay and emission data are from ENDF/B-VIII.0; the D-value follows NP-067-24; the gamma constant is the ambient dose equivalent H*(10) at 1 m, computed from ICRP-107 spectra.

How to use the data

Half-life and specific activity let you recalculate the activity of a Cm-250 source to the delivery or disposal date — use the decay calculator. Gamma lines with yields identify the nuclide from a spectrum and pick the line for gamma spectrometry; the gamma constant Γ gives the dose rate at a distance, while the D-value and A1/A2 set the source category and the package type for transport.