All tools

Nuclide reference

Dy-165 — Dysprosium-165

The half-life of Dy-165 is 2.334 h. Main decay mode: β⁻ decay to Ho-165 (100%).

Identification

Element
Dysprosium (Dy)
Atomic number Z
66
Mass number A
165
State
Radioactive

Key quantities

Half-life
2.334 h
Specific activity
3.011e+17 Bq/g
Gamma constant Γ
—
A1 / A2 for transport (SSR-6, НП-053-16)
0.9 TBq / 0.6 TBq
D-value (НП-067-24)
3 TBq

Decay modes

  • β⁻ decay → Ho-165 — 100 %

Main gamma lines

Energy, keVYield, %
47.548 · X-ray line4.938
94.73.8
46.701 · X-ray line2.772
361.680.904
633.4150.6126
715.3280.578
279.7630.5343
545.8340.1721
565.7180.1364
620.6350.1003

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

Alpha and beta particles

RadiationEnergy, keVYield, %
β⁻, E max1,286.783
1,19215
291.611.7
720.950.165

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.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.

Dysprosium-165 (Dy-165) — reference data

What is in the card

This card gathers the key data of radionuclide Dy-165 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 Dy-165 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.