How does electron capture work?

Electron capture is a process in which a proton-rich nucleus absorbs an inner-shell electron.

During electron capture, a proton-rich nucleus captures an inner-shell electron, typically from the K-shell, which combines with a proton to form a neutron and a neutrino. This process reduces the atomic number of the nucleus by one and increases the neutron-to-proton ratio, making the nucleus more stable. The energy released during electron capture is carried away by the neutrino, which is a neutral, low-mass particle that interacts weakly with matter.

Electron capture is a type of radioactive decay that occurs in certain isotopes, such as potassium-40, which decays to argon-40 via electron capture. This process is also important in the formation of neutron stars, where the intense gravitational fields can cause electron capture to occur in the nuclei of atoms, leading to the formation of neutron-rich matter.

Electron capture can be detected by observing the characteristic X-rays that are emitted when the electron vacancy is filled by an outer-shell electron. This technique is used in X-ray spectroscopy to identify the elements present in a sample.

Overall, electron capture is an important process in nuclear physics and has applications in fields such as astrophysics and materials science.