密度高、成像分辨率高、成像速度快的X射线数字成像检测需要高能微焦点大剂量X射线源，高品质电子源是实现这一X射线源的关键手段。基于中国工程物理研究院太赫兹自由电子激光的主加速器，验证了低发射度、低能散度的高亮度电子束实现高能微焦点的可行性，得到电子束半高全宽尺寸小于70 μm的9 MeV微焦点，并初步开展成像实验，双丝像质计焦斑清晰分辨9D号丝，丝直径0.13 mm。

High-density, high-resolution, and high-speed X-ray digital imaging detection requires a high-energy microfocus and high-dose X-ray source. A high quality electron beam source is the key means to achieve this X-ray source. Based on the main accelerator of the terahertz free electron laser of the China Academy of Engineering Physics (CTFEL), a high-energy microfocus X-ray source achieved by the high-brightness electron beam with low emittance and low energy spread was verified. The 9 MeV electron beam with full width at half-maximum of less than 70 μm was obtained. An initial imaging experiment was also carried out. The focal spot of the dual-wire image quality meter clearly distinguished the 9D wire with a wire diameter of 0.13 mm.