सभी tools

Nuclide reference

At-217 — Astatine-217

At-217 की half-life 32.3 ms है। मुख्य decay mode: α decay → Bi-213 (99.99%)।

Identification

तत्व
Astatine (At)
Atomic number Z
85
Mass number A
217
State
Radioactive

Key quantities

Half-life
32.3 ms
विशिष्ट गतिविधि
5.955e+22 Bq/g
Gamma constant Γ
—
D-value (НП-067-24)
—

Decay modes

  • α decay → Bi-213 — 99.99 %
  • β⁻ decay → Rn-217 — 0.007 %

Main gamma lines

Energy, keVYield, %
257.90.0287
593.10.0115
335.330.0062
758.90.0049

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

Alpha and beta particles

RadiationEnergy, keVYield, %
α7,066.999.89
6,813.80.036
6,484.70.021

Related calculators

Decayगतिविधि ↔ द्रव्यमानDose rate

इसी element के अन्य isotopes

At-211
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।

Astatine-217 (At-217) — reference data

What is in the card

This card gathers the key data of radionuclide At-217 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 At-217 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.