Electron Capture (denoted or ec)
Neutron deficient nuclides can also attain stability by capturing an electron from the inner K orL shells of the atomic orbits. As a result, a proton in the nucleus transforms to a neutron i.e.
The process is similar to decay in that the charge of the nucleus decreases by 1. The ed decay process can be described by:
and the daughter is usually produced in an excited state . The resulting nucleus is unstable and decays by the ejection of a neutrino (ν) and the emission of an X-ray when the electron vacancy in the K or L shell is filled by outer orbital electrons.
J. Magill and J. Galy, Radioactivity Radionuclides Radiation Springer Verlag, 2005