Nuclide reference

Ac-227 — Actinium-227

Ac-227 की half-life 21.772 years है। मुख्य decay mode: β⁻ decay → Th-227 (98.62%)।

Identification

तत्व
Actinium (Ac)
Atomic number Z
89
Mass number A
227
State
Radioactive

Key quantities

Half-life
21.772 years
विशिष्ट गतिविधि
2.676e+12 Bq/g
Gamma constant Γ
—
परिवहन के लिए A1 / A2 (SSR-6)
0.9 TBq / 0.00009 TBq
D-value (НП-067-24)
0.04 TBq

Decay modes

  • β⁻ decay → Th-227 — 98.62 %
  • α decay → Fr-223 — 1.38 %

Main gamma lines

Energy, keVYield, %
83.789 (Ra-223) · X-ray line24.07
235.96 (Th-227)17.3
81.071 (Ra-223) · X-ray line14.6
269.463 (Ra-223)13.95
351.07 (Bi-211)13.07
50.13 (Th-227)11.24
271.23 (Rn-219)10.84
256.23 (Th-227)9.393
401.81 (Rn-219)6.613
154.208 (Ra-223)5.72

Includes daughter nuclides in equilibrium: Th-227, Ra-223, Rn-219, Po-215, Pb-211, Bi-211, Tl-207 (yield per decay of Ac-227); the emitting nuclide is in brackets. Equilibrium is reached in about 130 d. Equilibrium with radon requires a sealed source.

Alpha and beta particles

RadiationEnergy, keVYield, %
α4,953.30.6583
6,819.1 (Rn-219)79.7
7,386.1 (Po-215)100.3
6,622.9 (Bi-211)83.85
β⁻, E max44.854
35.535
1,367 (Pb-211)91.64
1,418 (Tl-207)99.83

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.

Actinium-227 (Ac-227) — reference data

What is in the card

This card gathers the key data of radionuclide Ac-227 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 Ac-227 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.