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Nuclide reference

Sb-126m — Antimony-126m

The half-life of Sb-126m is 19.15 min. Main decay mode: β⁻ decay to Te-126 (86%).

Identification

Element
Antimony (Sb)
Atomic number Z
51
Mass number A
126
State
Radioactive

Key quantities

Half-life
19.15 min
Specific activity
2.883e+18 Bq/g
Gamma constant Γ
—
D-value (НП-067-24)
—

Decay modes

  • β⁻ decay → Te-126 — 86 %
  • isomeric transition → Sb-126 — 14 %

Main gamma lines

Energy, keVYield, %
414.585.67
666.185.67
694.882.25
1,034.91.799
6201.542
928.21.285
27.472 · X-ray line0.7227
1,061.60.514
27.202 · X-ray line0.3882
1,476.10.3427

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

Alpha and beta particles

RadiationEnergy, keVYield, %
β⁻, E max1,915.282.8
1,2953.392
987.11.297
853.60.8579

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

Related calculators

DecayActivity ↔ massDose rate
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.

Antimony-126m (Sb-126m) — reference data

What is in the card

This card gathers the key data of radionuclide Sb-126m 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 Sb-126m 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.