Nuclide reference

Ra-225 — Radium-225

Ra-225 की half-life 14.9 d है। मुख्य decay mode: β⁻ decay → Ac-225 (100%)।

Identification

तत्व
Radium (Ra)
Atomic number Z
88
Mass number A
225
State
Radioactive

Key quantities

Half-life
14.9 d
विशिष्ट गतिविधि
1.441e+15 Bq/g
Gamma constant Γ
—
परिवहन के लिए A1 / A2 (SSR-6)
0.2 TBq / 0.004 TBq
D-value (НП-067-24)
0.1 TBq

Decay modes

  • β⁻ decay → Ac-225 — 100 %

Main gamma lines

Energy, keVYield, %
4030
15.636 · X-ray line5.788
12.6432 · X-ray line5.471

Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.

Alpha and beta particles

RadiationEnergy, keVYield, %
β⁻, E max316.9169.5
35730.5

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.

Radium-225 (Ra-225) — reference data

What is in the card

This card gathers the key data of radionuclide Ra-225 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 Ra-225 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.