Xe
Xenon
Z = 54 · Noble Gas · 131.3 u
Nuclear Engineering Significance
Xe-135 has the highest thermal neutron absorption cross-section of any known nuclide (σ_a ≈ 2.65 × 10⁶ b). It is the dominant fission product poison, causing xenon transients and spatial oscillations in large thermal reactors. Xenon dynamics directly affect reactor control strategy, startup procedures, and power maneuvering capability.
Basic properties
- Atomic number (Z)
- 54
- Standard atomic mass
- 131.3 u
- Category
- Noble Gas
Isotopes & cross-section data
| Isotope | Mass (A) | Half-life | ZAID | Libraries |
|---|---|---|---|---|
| Xe-131 | 131 | Stable | .80c.71c | |
| Xe-133 | 133 | 5.2475 d | .80c.71c | |
| Xe-135 | 135 | 9.14 h | .80c.71c |