电子亲和能是原子分子的基本属性之一，其对化学反应、等离子物理、大气物理化学、天体物理等都很重要。目前的一些重要的原子分子的电子亲和能测量精度不高，对分子不确定度在10 meV左右，对一些原子不确定度有在1 meV左右，如Fe原子的电子亲和能0.151(3) eV。计划利用冷离子阱和慢电子成像相结合的方法对原子分子的电子亲和能进行精密测量，使用该方法可以将测量精度提高10倍以上。对于分子的电子亲和能测量精度将好于1meV，对于原子利用极慢电子成像中的干涉效应甚至可以将测量精度提高到0.001 meV。对于一些极性分子，还可以通过偶极束缚态，对分子的电子结构实现接近自然线宽或激光线宽的精密测量。精密测量的实验结果将成为各种理论计算的检验标准。

Electron affinity (EA) is one of the most basic properties of atoms and molecules. It is a key parameter in many fundamental areas, such as chemical reactions, plasma physics, atmosphere chemistry and physics, astrophysics. At current stage, the experimental accuracy of some atomic or molecular EAs is quite low. The typical uncertainty of molecular EAs is about 10 meV, while 1 meV for atoms. For example, the EA of Fe atom is 0.151(3) eV. We proposed a new method using slow electron imaging combined with a cold ion trap to improve the accuracy at least one order of magnitude. The measured uncertainty of molecular EAs will lower than 1 meV. The atomic EAs determined using the interference in the extremely slow electron imaging will approached the accuracy 0.001 meV. For some dipolar molecules, the accuracy may achieve the natural line width or the laser line width using the dipole-bound state. The high precision experimental values will provide benchmarks for various theoretical models.