All tools

Nuclide reference

Th-230 — Thorium-230

The half-life of Th-230 is 75,380 years. Main decay mode: α decay to Ra-226 (100%).

Identification

Element
Thorium (Th)
Atomic number Z
90
Mass number A
230
State
Radioactive

Key quantities

Half-life
75,380 years
Specific activity
762,900,000 Bq/g
Gamma constant Γ
—
A1 / A2 for transport (SSR-6, НП-053-16)
10 TBq / 0.001 TBq
D-value (НП-067-24)
0.07 TBq

Decay modes

  • α decay → Ra-226 — 100 %
  • spontaneous fission — 2.5e-11 %

Main gamma lines

Energy, keVYield, %
12.3 · X-ray line7.629
67.6720.3767
143.8720.04878
253.7290.01111
186.0530.008787
253.80.0008484

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

Alpha and beta particles

RadiationEnergy, keVYield, %
α4,68776.3
4,620.523.4
4,479.80.12
4,438.40.03

Related calculators

DecayActivity ↔ massSource categoryDose rateA1/A2 and package type

Other isotopes of this element

Th-228Th-232
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.

Thorium-230 (Th-230) — reference data

What is in the card

This card gathers the key data of radionuclide Th-230 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 Th-230 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.