Identification

तत्व: Helium (He)
Atomic number Z: 2
Mass number A: 5
State: Radioactive

Key quantities

Half-life: 7.595e-10 ps
विशिष्ट गतिविधि: 1.099e+44 Bq/g
Gamma constant Γ: —
D-value (НП-067-24): —

Decay modes

α decay — 100 %

Related calculators

Decay गतिविधि ↔ द्रव्यमान Dose 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 1 m पर H*(10) है, ICRP-107 spectra (NIST µ_en/ρ, ICRP-74 Table A.21) से गणना की गई, equilibrium में short-lived progeny सहित (जैसे Cs-137/Ba-137m, Ra-226 series); specific activity molar mass M ≈ mass number A का उपयोग करती है।

Helium-5 (He-5) — reference data

What is in the card

This card gathers the key data of radionuclide He-5 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 He-5 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.