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Nuclide reference

H-4 — Hydrogen-4

The half-life of H-4 is 9.9065e-11 ps. Main decay mode: neutron emission to H-3 (100%).

Identification

Element
Hydrogen (H)
Atomic number Z
1
Mass number A
4
State
Radioactive

Key quantities

Half-life
9.9065e-11 ps
Specific activity
1.053e+45 Bq/g
Gamma constant Γ
—
D-value (НП-067-24)
—

Decay modes

  • neutron emission → H-3 — 100 %

Related calculators

DecayActivity ↔ massDose rate

Other isotopes of this element

H-3
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.

Hydrogen-4 (H-4) — reference data

What is in the card

This card gathers the key data of radionuclide H-4 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 H-4 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.