Nuclide reference
Xe-123 — Xenon-123
The half-life of Xe-123 is 2.08 h. Main decay mode: β⁺ decay / electron capture to I-123 (100%).
Identification
- Element
- Xenon (Xe)
- Atomic number Z
- 54
- Mass number A
- 123
- State
- Radioactive
Key quantities
- Half-life
- 2.08 h
- Specific activity
- 4.532e+17 Bq/g
- Gamma constant Γ
- —
- A1 / A2 for transport (SSR-6, НП-053-16)
- 2 TBq / 0.7 TBq
- D-value (НП-067-24)
- 0.09 TBq
Decay modes
- β⁺ decay / electron capture → I-123 — 100 %
Main gamma lines
| Energy, keV | Yield, % |
|---|---|
| 148.9 | 48.9 |
| 510.999 · annihilation 511 keV | 46.43 |
| 28.612 · X-ray line | 39.99 |
| 28.318 · X-ray line | 21.54 |
| 178.1 | 14.91 |
| 330.2 | 8.558 |
| 1,093.4 | 2.787 |
| 899.6 | 2.445 |
| 1,113.1 | 1.565 |
| 1,807.3 | 1.247 |
Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.
Alpha and beta particles
| Radiation | Energy, keV | Yield, % |
|---|---|---|
| β⁺, E max | 1,524.1 | 17.9 |
| 1,495 | 4.1 | |
| 1,342.7 | 1.1 | |
| 624.31 | 0.048 |
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 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.