Nuclide reference
Kr-85m — Krypton-85m
The half-life of Kr-85m is 4.48 h. Main decay mode: β⁻ decay to Rb-85 (78.6%).
Identification
- Element
- Krypton (Kr)
- Atomic number Z
- 36
- Mass number A
- 85
- State
- Radioactive
Key quantities
- Half-life
- 4.48 h
- Specific activity
- 3.045e+17 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 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, keV | Yield, % |
|---|---|
| 151.195 | 74.98 |
| 304.87 | 14.02 |
| 12.648 · X-ray line | 2.216 |
| 13.395 · X-ray line | 1.175 |
| 129.81 | 0.2999 |
| 451 | 0.01125 |
| 731.6 | 0.007498 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁻, E max | 841.06 | 78.3 |
| 711.26 | 0.3 | |
| 260.38 | 0.019 |
For β⁻ the endpoint (maximum) energy of the spectrum is given. ENDF/B-VIII.0.
Related calculators
Other isotopes of this element
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.