electron capture 

https://doi.org/10.1351/goldbook.E01980
A nuclear transformation in which the nucleus captures an orbital electron. Often the shell, from which the electron is captured, is indicated. (K-, L-, etc.).
Source:
PAC, 1982, 54, 1533. (Glossary of terms used in nuclear analytical chemistry (Provisional)) on page 1537 [Terms] [Paper]