Neutronenabsorber

Neutronenabsorber are materials that have a high probability of capturing neutrons. This property makes them essential in various nuclear applications, particularly in nuclear reactors and nuclear weapons. In nuclear reactors, neutron absorbers are used to control the rate of nuclear fission. They can be incorporated into control rods, which are physically inserted or withdrawn from the reactor core to adjust the neutron population. Materials like Cadmium, Boron, and Hafnium are common neutron absorbers due to their large neutron capture cross-sections.

The mechanism by which neutron absorbers work involves their atomic nuclei interacting with incident neutrons. Upon capturing a neutron, the nucleus may become unstable and undergo a nuclear reaction, often emitting gamma rays or other particles, but crucially, it removes a neutron from the chain reaction. This reduction in available neutrons slows down or stops the fission process. In some cases, the absorbed neutron can lead to the transmutation of the absorber material into a different isotope.

Beyond reactor control, neutron absorbers also play a role in nuclear fuel reprocessing and the safe storage of spent nuclear fuel, where they help prevent criticality accidents by absorbing stray neutrons. In nuclear weapons, neutron absorbers can be used to quench a premature or uncontrolled chain reaction. The choice of neutron absorber depends on factors such as its absorption cross-section for different neutron energies, its chemical and physical properties, and its cost.