xenon131

Xenon-131 (131Xe) is a radioactive isotope of the noble gas xenon (atomic number 54) with a mass number of 131. It contains 54 protons and 77 neutrons. It is a synthetic nuclide, not found in appreciable quantities in natural xenon, and is produced mainly as a fission product in nuclear reactors and by neutron capture on xenon or related isotopes.

Decay and half-life: 131Xe decays primarily by beta-minus emission to cesium-131 (131Cs). The decay is accompanied by gamma radiation from the daughter nucleus. Its half-life is short on geological timescales, typically on the order of days to weeks, making 131Xe a transient fission product compared with many stable xenon isotopes.

Production and occurrence: In reactors, 130Xe can capture a neutron to become 131Xe, and direct fission of heavy elements also yields 131Xe among the products. As a gas, 131Xe can be released from fuel and contribute to the radiological inventory in reactor containment or during fuel reprocessing.

Chemical and physical properties: As a noble gas, 131Xe retains xenon's inert chemistry and exists as a gas at room temperature. Its radiological decay is the primary hazard, emitting beta particles and gamma rays during decay.

Applications and safety: Xenon isotopes including 131Xe are of interest in reactor physics and radiological safety due to their role in fission product inventories and neutron-poison dynamics. Handling requires standard radiological controls to minimize inhalation and environmental release.