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Nuclide reference

Rb-81 — Rubidium-81

Rb-81 की half-life 4.572 h है। मुख्य decay mode: β⁺ decay / electron capture → Kr-81m (95.67%)।

Identification

तत्व
Rubidium (Rb)
Atomic number Z
37
Mass number A
81
State
Radioactive

Key quantities

Half-life
4.572 h
विशिष्ट गतिविधि
3.131e+17 Bq/g
Gamma constant Γ
—
परिवहन के लिए A1 / A2 (SSR-6)
2 TBq / 0.8 TBq
D-value (НП-067-24)
0.1 TBq

Decay modes

  • β⁺ decay / electron capture → Kr-81m — 95.67 %
  • β⁺ decay / electron capture → Kr-81 — 4.328 %

Main gamma lines

Energy, keVYield, %
190.46 (Kr-81m)64.76
510.999 · annihilation 511 keV54.39
446.1523.5
12.648 · X-ray line23.37
12.596 · X-ray line12.12
510.435.405
456.733.055
537.62.256
1,368.10.8695
803.720.8437

Includes daughter nuclides in equilibrium: Kr-81m (yield per decay of Rb-81); the emitting nuclide is in brackets. Equilibrium is reached in about 1.5 min.

Alpha and beta particles

RadiationEnergy, keVYield, %
β⁺, E max1,026.325
580.151.82
516.140.28
1,2170.06

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

Related calculators

Decayगतिविधि ↔ द्रव्यमानSource categoryDose rateA1/A2 और package type
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.

Rubidium-81 (Rb-81) — reference data

What is in the card

This card gathers the key data of radionuclide Rb-81 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 Rb-81 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.