β衰变包括3种方式：β-衰变、β+衰变和电子俘获(EC).其中电子俘获(EC)这种衰变可以表示为即母核俘获1个核外轨道电子使核内1个质子转变为中子，并放出1个中微子，所以子核的电荷数变为Z-1，而质量数保持不变.在一般情况下，K层上的电子被原子核俘获的居多，因为K层最靠近原子核，被俘获的概率最大，但是L层上的电子被俘获的概率也是存在的.原子核在俘获了电子之后，子核原子的K层或L层上将出现一个电子空位，当某一外层电子来填补这个空位时，可能会出现下面两种情况之一：要么以标识X射线的形式将多余的能量释放，要么将多余的能量交给另一层上的其他电子，此电子获得能量而脱离原子，成为俄歇电子.伴有X射线或俄歇电子的发射是K俘获过程的标志.

There are three ways of beta decay: beta-decay, beta-decay and electron capture (EC). The decay of electron capture (EC) can be expressed as that the mother nucleus captures an extranuclear orbital electron, transforms a proton into a neutrino and releases a neutrino, so the charge number of the nucleus becomes Z-1, while the mass number remains unchanged. In general, the electrons in the K tianchuangd.89ix.comtianchuang.89ix.comtongfengqiw.89ix.comtongfengqi.89ix.comchuanxian.89ix.com

pvcguanjian.89ix.comlayer are mostly captured by the nucleus because of the fact that the electron in the K layer is captured by the nucleus. For the K layer closest to the nucleus, the probability of electron capture is the greatest, but the probability of electron capture on the L layer also exists. After the electron is captured, there will be an electron vacancy in the K or L layer of the nuclear atom. When an outer layer electron fills the vacancy, one of the following two situations may occur: Either the excess energy will be released in the form of labeling X-ray. Release, or transfer excess energy to other electrons on another layer, which acquires energy and breaks away from atoms to become Auger electrons. Emission with X-rays or Auger electrons is a sign of K capture process.