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Nuclide reference

Eu-152m — Europium-152m

The half-life of Eu-152m is 9.3116 h. Main decay mode: β⁻ decay to Gd-152 (73%).

Identification

Element
Europium (Eu)
Atomic number Z
63
Mass number A
152
State
Radioactive

Key quantities

Half-life
9.3116 h
Specific activity
8.192e+16 Bq/g
Gamma constant Γ
—
A1 / A2 for transport (SSR-6, НП-053-16)
0.8 TBq / 0.8 TBq
D-value (НП-067-24)
0.2 TBq

Decay modes

  • β⁻ decay → Gd-152 — 73 %
  • β⁺ decay / electron capture → Sm-152 — 27 %

Main gamma lines

Energy, keVYield, %
841.59414.17
40.119 · X-ray line13.37
963.3911.67
121.7777.002
45.418 · X-ray line2.594
344.312.377
1,314.670.931
1,3890.7484
970.350.5879
562.930.2197

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

Alpha and beta particles

RadiationEnergy, keVYield, %
β⁻, E max1,864.469.61
1,520.11.68
549.751.59
816.550.123

For β⁻ the endpoint (maximum) energy of the spectrum is given. ENDF/B-VIII.0.

Related calculators

DecayActivity ↔ massSource categoryDose rateA1/A2 and package type

Other isotopes of this element

Eu-152Eu-154
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.

Europium-152m (Eu-152m) — reference data

What is in the card

This card gathers the key data of radionuclide Eu-152m 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 Eu-152m 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.