Beta Decay - Electron Capture (K-capture)

Electron Capture (K-capture)

In all the cases where β+ decay is allowed energetically, the electron capture process, when an atomic electron is captured by a nucleus with the emission of a neutrino, is also allowed:

^A_ZN + e^- \rightarrow ~ ^{~~~A}_{Z-1}N' + {\nu_e}

The emitted neutrino is mono-energetic. In proton-rich nuclei where the energy difference between initial and final states is less than 2mec2, β+ decay is not energetically possible, and electron capture is the sole decay mode.

This decay is also called K-capture because the innermost electron of an atom belongs to the K-shell of the electronic configuration of the atom, and this has the highest probability to interact with the nucleus.

There is an analogous process possible in theory in antimatter: antiproton-rich antimatter radioisotopes might decay via an analogous process of positron capture, but in practice no such complex antimatter nuclides have either been discovered or artificially constructed.

Read more about this topic:  Beta Decay

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