Nuclide reference

Kr-85m — Krypton-85m

Kr-85m की half-life 4.48 h है। मुख्य decay mode: β⁻ decay → Rb-85 (78.6%)।

Identification

तत्व
Krypton (Kr)
Atomic number Z
36
Mass number A
85
State
Radioactive

Key quantities

Half-life
4.48 h
विशिष्ट गतिविधि
3.045e+17 Bq/g
Gamma constant Γ
—
परिवहन के लिए A1 / A2 (SSR-6)
8 TBq / 3 TBq
D-value (НП-067-24)
0.5 TBq

Decay modes

  • β⁻ decay → Rb-85 — 78.6 %
  • isomeric transition → Kr-85 — 21.4 %

Main gamma lines

Energy, keVYield, %
151.19574.98
304.8714.02
12.648 · X-ray line2.216
13.395 · X-ray line1.175
129.810.2999
4510.01125
731.60.007498

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

Alpha and beta particles

RadiationEnergy, keVYield, %
β⁻, E max841.0678.3
711.260.3
260.380.019

For β⁻ the endpoint (maximum) energy of the spectrum is given. ENDF/B-VIII.0.

Related calculators

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।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.

Krypton-85m (Kr-85m) — reference data

What is in the card

This card gathers the key data of radionuclide Kr-85m 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 Kr-85m 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.