原子与绝缘体表面碰撞能高效产生负离子的研究为寻找强流负离子源、空间中性粒子探测等提供了新途径，因而受到了人们较多的关注。解离是影响负离子最终份额至关重要的因素，直接采用负离子束与绝缘体表面散射是研究负离子解离的最佳途径，但受实验条件的限制，该实验较难开展，因此人们对绝缘体表面负离子解离机制并不了解。兰州大学拥有运行良好的低能负离子源，为我们开展keV能量负离子束与绝缘晶体表面散射实验提供了便利条件。本项目拟在实验上，基于掠射和背散射布局，采用位置灵敏和飞行时间技术考察绝缘体能带结构、负离子亲和能级、入射能、入射角以及表面阴阳离子与负离子解离的内在联系;在理论上，发展本课题组提出的负离子解离模型，帮助理解实验结果。通过本项目的研究，不仅能深入理解绝缘体表面负离子解离的动力学行为，而且将推动二次离子质谱、低能离子散射谱学、新型负离子源等技术的发展。

Negative ion formation occurs with a high probability during the interaction of energetic atoms with insulator surfaces, which provides the new approach in application to large-current negative-ion sources and neutral-particle detection in space. Since the detachment is vital for the survival of the negative-ions, the best way to study the negative ion detachment is the negative ion scattering. However, such measurments are still fairly scarce because of the limit of the experimental conditions. In contrary, the negative-ion source in Lanzhou University works well and provides us with the good precondition. Based on grazing scattering and backscattering configurations, we use the position-sensitive and time-of-flight techniques to perform experimental studies. On one hand, this study focuses experimentally on the relationship between the detachment of negative ions and the bandgap of the insulator, the electron affinity, the incident energy and the incident angle, as well as the anion and cation on the surface; on the other hand, we will further develop the model proposed previously by our group to interpret the experimental results well. The combination of experiment and theory can not only reveal the mechanism related to the detachment of the negative ion, but also promote the development of secondary ion spectroscopy, low-energy ion scattering spectroscopy, and new negative ion sources, etc.