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Nuclide reference

Y-90 — Yttrium-90

The half-life of Y-90 is 2.6667 d. Main decay mode: β⁻ decay to Zr-90 (100%).

Identification

Element
Yttrium (Y)
Atomic number Z
39
Mass number A
90
State
Radioactive

Key quantities

Half-life
2.6667 d
Specific activity
2.013e+16 Bq/g
Gamma constant Γ
—
A1 / A2 for transport (SSR-6, НП-053-16)
0.3 TBq / 0.3 TBq
D-value (НП-067-24)
5 TBq

Decay modes

  • β⁻ decay → Zr-90 — 100 %

Alpha and beta particles

RadiationEnergy, keVYield, %
β⁻, E max2,279.899.99
519.080.0115

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
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.

Yttrium-90 (Y-90) — reference data

What is in the card

This card gathers the key data of radionuclide Y-90 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 Y-90 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.