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Nuclide reference

Pa-234 — Protactinium-234

The half-life of Pa-234 is 6.7 h. Main decay mode: β⁻ decay to U-234 (100%).

Identification

Element
Protactinium (Pa)
Atomic number Z
91
Mass number A
234
State
Radioactive

Key quantities

Half-life
6.7 h
Specific activity
7.396e+16 Bq/g
Gamma constant Γ
—
D-value (НП-067-24)
—

Decay modes

  • β⁻ decay → U-234 — 100 %

Main gamma lines

Energy, keVYield, %
17.0955 · X-ray line44.1
13.6102 · X-ray line41.7
131.318.55
94613.78
880.510.71
883.249.858
569.58.48
9258.056
926.727.42
733.397.102

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

Alpha and beta particles

RadiationEnergy, keVYield, %
β⁻, E max470.634
641.420.4
471.112.9
411.48

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.

Protactinium-234 (Pa-234) — reference data

What is in the card

This card gathers the key data of radionuclide Pa-234 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 Pa-234 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.